VALIDATION OF ELECTROANALYTICAL METHOD WITH … · Točnost metode se je preverila za koncentracije...

Bachelor Thesis

VALIDATION OF ELECTROANALYTICAL METHOD WITH ANTIMONY ELECTRODE FOR TRACE METAL

ANALYSIS

September, 2017 Aljaž Ramot

Aljaž Ramot

Validation of electroanalytical method with antimony electrode for trace metal analysis

Bachelor Thesis

Maribor, 2017

Validacija elektroanalizne metode z antimonovo

elektrodo za analizo težkih kovin v sledovih

Diplomsko delo visokošolskega strokovnega študijskega programa I.

stopnje

Študent: Aljaž Ramot

Študijski program: visokošolski strokovni študijski program I. stopnje

Kemijska tehnologija

Predvideni strokovni naslov: diplomirani inženir kemijske tehnologije (VS)

Mentor: doc. dr. Matjaž Finšgar

Komentor: asist. Barbara Petovar, mag. kem.

Maribor, 2017


I

Table of Contents

.......................................................................................................................................... IV Table of Contents ................................................................................................................. I Izjava.................................................................................................................................. II

Acknowledgments ............................................................................................................ III Validacija elektroanalizne metode z antimonovo elektrodo za analizo težkih kovin v

sledovih ................................................................................................................................... IV Povzetek ............................................................................................................................ IV Validation of electroanalytical method with antimony electrode for trace metal analysis V

Abstract .............................................................................................................................. V List of Tables .................................................................................................................... VI List of Figures ................................................................................................................. VII

List of Symbols and Abbreviations .................................................................................. IX 1. Introduction and identifying the problem ................................................................ 10

1.1. Identifying the problem .................................................................................... 10

1.2. Heavy metals .................................................................................................... 10 1.3. The effect of heavy metals on organisms and on the environment .................. 10 1.4. Validation of electroanalytical method ............................................................. 11

1.4.1. Limit of detection (LOD) and limit of quantitation (LOQ) ....................... 11 1.4.2. Linearity and calibration curve.................................................................. 11

1.4.3. Outliers per Dixon’s and Grubbs’ tests ..................................................... 11

1.4.4. RSD (relative standard deviation) ............................................................. 12

1.5. Scientific background ....................................................................................... 12 1.6. The Hypothesis, purpose and goal of the thesis ............................................... 13

2. Analytical method .................................................................................................... 14 2.1. Square-wave anodic stripping voltammetry (SWASV) ................................... 14

3. Experimental ............................................................................................................ 16

3.1. Cyclic voltammetry (CV) ................................................................................. 17

3.2. Materials ........................................................................................................... 19 4. Results and discussion ............................................................................................. 20

4.1. LOD and LOQ analysis .................................................................................... 20 4.2. Linearity ............................................................................................................ 22 4.3. Accuracy ........................................................................................................... 26

5. Conclusion ............................................................................................................... 33 6. References ................................................................................................................ 34

7. Življenjepis (CV) ..................................................................................................... 35


II

Izjava

Izjavljam, da sem diplomsko delo izdelal/a sam/a, prispevki drugih so posebej

označeni. Pregledal/a sem literaturo s področja diplomskega dela po naslednjih geslih:

Vir: Sciencedirect (http://www.sciencedirect.com/)

Gesla: Število

referenc

Anodic stripping voltammetry 35

Square-wave voltammetry 17

Heavy metals 48

Antimony film electrode 18

Vir: Google Books (http://books.google.com/)

Gesla: Število

referenc

Cyclic voltammetry 30

Antimony IN electroanalysis 25

Skupno število pregledanih člankov: 24

Skupno število pregledanih knjig: 6

Maribor, September 2017 Aljaž Ramot


III

Acknowledgments

I would like to thank my thesis advisor, doc. dr. Matjaž

Finšgar and co-advisor, asist. Barbara Petovar, mag. kem. The

door to their offices were always open whenever I had questions

about my writing. Special thanks go to my friend Vid Baklan for

proofreading this thesis. I would also like to thank my family

members, for their support and encouragement throughout my

life.


IV

Validacija elektroanalizne metode z antimonovo elektrodo za

analizo težkih kovin v sledovih

Povzetek

Namen diplomskega dela je validacija elektroanalizne metode z antimonovo elektrodo za

analizo težkih kovin v sledovih. Validacija se je pričela z določevanjem meje zaznavnosti

(LOD) in meje kvantifikacije (LOQ), nadaljevala z določanjem linearnosti in končala z

določanjem točnosti in natančnosti. Analiza težkih kovin je bila izvedena s square-wave

anodno striping voltametrijo (SWASV), za testiranje reverzibilnosti sistema

[Fe(CN)6]-3/[Fe(CN)6]

-4 pa smo uporabili metodo ciklične voltametrije (CV). Vse analize so

bile izvedene v 0,01 M raztopini HCl.

Meje LOD in LOQ ni mogoče določiti z dovolj veliko gotovostjo, saj ima metoda tako

nizko LOD, da je bila kontaminacija s težkimi kovinami, tudi v ultra čisti kislini, prevelika.

Metoda ima linearen odziv pri potencialih depozicije -1,2 V, -1,1 V in -1,0 V vs. Ag/AgCl za

Pb(II) in Cd(II) v območju od 14,6 µg L-1 do 100,0 µg L-1. Točnost metode se je preverila za

koncentracije 15 µg L-1, 25 µg L-1, 30 µg L-1, 40 µg L-1 pri vseh treh potencialih depozicije.

Ugotovljeno je bilo, da je metoda najbolj točna in natančna pri potencialu depozicije -1,1 V

vs. Ag/AgCl.

Ključne besede: Analiza težkih kovin, analitika sledov, antimonova elektroda, SWASV,

voltametrija.

UDK: 543.55:549.25(043.2)


V

Validation of electroanalytical method with antimony electrode for

trace metal analysis

Abstract

The purpose of this thesis is to validate the electroanalytical method with an antimony

electrode for trace metal analysis. The validation began with the determination of the limit of

detection (LOD) and the limit of quantification (LOQ), proceeded with determining the

method’s linearity and concluded with determination of accuracy and precision. The trace

metal analysis was conducted via square-wave anodic stripping voltammetry (SWASV).

Cyclic voltammetry (CV) was used to test the reversibility of the [Fe(CN)6]-3/[Fe(CN)6]

-4

system. All the analyses were conducted in a 0.01 M HCl solution.

The LOD and LOQ were not possible to report with certainty, since the method has such

a low LOD that the contamination with heavy metals, even in ultrapure acid, was too high.

The method had a linear response at deposition potentials of -1.2 V, -1.1 V and -1.0 V vs.

Ag/AgCl for Pb(II) and Cd(II) from 14.6 µg L-1 to 100.0 µg L-1. The precision of the method

was tested at 15 µg L-1, 25 µg L-1, 30 µg L-1 and 40 µg L-1 for all three deposition potentials.

The results have shown that the method is the most accurate and precise at a deposition

potential of -1.1 V vs. Ag/AgCl.

Key words: heavy metal analysis, trace analysis, antimony electrode, SWASV, voltammetry

UDK: 543.55:549.25(043.2)


VI

List of Tables

Table 3-1: Results were similar to the proposed guidelines mentioned above ....................... 17

Table 4-1: Linearity regression analysis of Cd(II) plot at a -1.2 V deposition potential for all

three curves. ............................................................................................................................ 23


three curves. ............................................................................................................................ 24


three curves. ............................................................................................................................ 24

Table 4-4: Linearity regression analysis of Pb(II) plot at a -1.2 V deposition potential for both

curves. ..................................................................................................................................... 25


curves. ..................................................................................................................................... 25


curves. ..................................................................................................................................... 26

Table 4-7: Recovery determined for concentration at 15.0 µg L-1 ........................................ 29

Table 4-8: Recovery determined for concentration at 25.0 µg L-1 ......................................... 30

Table 4-9: Recovery determined for concentration at 30.0 µg L-1 ......................................... 30

Table 4-10: Recovery determined for concentration at 40.0 µg L-1 ....................................... 31


VII

List of Figures

Figure 2-1: An example of anodic stripping voltammogram ................................................. 14

Figure 2-2: (A) potential waveform, (B) one potential cycle, (C) voltammogram in SWV. The

response consists out of a forward (anodic, ψf), backward (cathodic, ψb) and net (ψnet)

component [15]. ...................................................................................................................... 15

Figure 3-1: Polishing cloth and the aluminium oxide paste ................................................... 16

Figure 3-2: The linear plot of the peak current vs. square root of the scan rate, which indicates

that the reaction is controlled by diffusion. ............................................................................ 18

Figure 3-3: Cyclic voltammogram of potassium ferricyanide, at different scan rates given in

Table 3-1, starting with 10 mV/s and increasing to 200 mV/s. .............................................. 18

Figure 4-1: The reduction peaks for Cd(II) (at -0.75 V) and Pb(II) (at -0.36 V)in the blank

0.01 M HCl solution using different deposition potentials: -1.0 V (blue curve), -1.1 V (red

curve) and -1.2 V (green curve). ............................................................................................. 20

Figure 4-2: The reduction peaks for Cd(II) (at -0.75 V) and Pb(II) (at -0.33 V) in the blank

solution in ultrapure HCl acid using different deposition potentials: : -1.0 V (blue

curve), -1.1 V (red curve) and -1.2 V (green curve). .............................................................. 21

Figure 4-3: Concentration range for Pb(II) from 1.0 µg L-1 to 106.3 µg L-1. Points represent

values at different deposition potentials, blue at -1.2 V, orange at -1.1 V and gray at -1.0 V.

................................................................................................................................................ 22

Figure 4-4: Concentration range for Cd(II) from 1.0 µg L-1 to 106.3 µg L-1. Points represent

values at different deposition potentials, blue at -1.2 V, orange at -1.1 V and gray at -1.0 V.

................................................................................................................................................ 22

Figure 4-5: Three replicates for the resulting calibration plot linear for Cd(II) response at

a -1.2 V deposition potential. Linearity regression analysis parameters for all three replicates

are given in Table 4-1. ............................................................................................................ 23







Figure 4-8: Two replicates for the resulting calibration plot linear for Pb(II) response at

a -1.2 V deposition potential. Linearity regression analysis parameters for both replicates are

given in Table 4-4. .................................................................................................................. 25



given in Table 4-5. .................................................................................................................. 25



given in Table 4-6. .................................................................................................................. 26

Figure 4-11: Calibration curve for Cd(II) at a deposition potential of -1.2 V. ....................... 27



Figure 4-14: Calibration curve for Pb(II) at a deposition potential of -1.2 V. ....................... 28


VIII

Figure 4-15: Calibration curve for Pb(II) at a deposition potential of -1.1 V. ....................... 28

Figure 4-16: Calibration curve for Pb(II) at a deposition potential of -1.0 V. ........................ 29


IX

List of Symbols and Abbreviations

Symbols

Ipa Anodic current peak [A]

Ipc Cathodic current peak [A]

Ip Peak current [A]

Epa Anodic potential peak [V]

Epc Cathodic potential peak [V]

Ep Peak potential [V]

Esw Square wave amplitude [V]

Greek Symbols

Ψf anodic component

Ψb cathodic component

Ψnet net component

mass concentration [g/L]

υ scan rate [V/s]

Abbreviations

APL Acute Promyelocytic Leukaemia

ASV Anodic Stripping Voltammetry

SbFE Antimony Film Electrode

SbFGCE Antimony Film Modified Glassy Carbon Electrode

CV Cyclic Voltammetry

GCE Glassy Carbon Electrode

LOD Limit of Detection

LOQ Limit of Quantification

RSD Relative Standard Deviation

SWASV Square-wave Anodic Stripping Voltammetry

SWV Square-wave Voltammetry

SHE Standard Hydrogen Electrode

SCP Stripping Chronopotentiometry


10

1. Introduction and identifying the problem

1.1. Identifying the problem Heavy metals are naturally occurring materials that can be found in the Earth’s crust [1].

They are known to be toxic for humans and other organisms even in small quantities, which is

why constant supervision of the amount of heavy metals in nature is of paramount importance.

With supervision, possible contaminations can be discovered faster, thus decreasing the impact

of heavy metals on the environment [2].

In the analysis of heavy metals in aquatic environments, the conventional mercury electrode

was mostly used due to its unique attributes [3]. Its 60-year dominance seems to be coming to

an end, however, since it is being increasingly replaced by newer, environmentally-friendlier,

electrodes [4]. The replacement of Hg-electrodes is further supported by the European Union,

which banned the authorisation of mercury from 2015 onwards with a directive

(European Directive 2008/105/EC) [3]. The development of new electroanalytical methods is

inevitable despite already familiar alternatives, such as the bismuth electrode, since the entire

field of stripping analysis is moving towards using mercury-free electrodes, which means that

development in this area is of vital importance [4].

1.2. Heavy metals There are several definitions for the term ‘heavy metals’, but it is agreed that elements

classified as heavy metals have a relatively high density when compared to water (at least five

times as high) [5]. They also have a similar configuration of electrons in their outer orbitals [2].

Over 50 elements can be classified as heavy metals, including some metalloids, lanthanides and

actinides.

1.3. The effect of heavy metals on organisms and on the environment

The occurrence of heavy metals is a completely natural phenomenon, which occurs for

example during volcano eruptions. However, there is a growing concern regarding the effects

of heavy metals on health in recent years, since the environment is becoming more and more

artificially contaminated with heavy metals [5]. Several large industries have contributed to the

rise in concentration of heavy metals in our ecosystem over the last few decades and human

exposure to these metals has increased due to new developments in the fields of agriculture,

industry and technology [2, 5].

The issue with heavy metals is that they cannot be degraded or destroyed, while being

bioaccumulative, meaning that their quantity in an organism increases over time, even though

the organism itself does not change. As a result, heavy metals are accumulating at a faster rate

than the organism can extract them [1]. Most heavy metals are classified as harmful chemicals,

but some can disturb endocrine glands or can even be carcinogens [2]. Their toxicity and their

effect on a system depend on several factors, such as the amount consumed, the level of

exposure and the genes, age and gender of individual exposed subjects [5]. It is important to

recognise that heavy metals enter our body every day via food, water and air, but in small,

harmless quantities. Smaller amounts of metals, such as copper, zinc and selenium, are even

essential to the human metabolism [1]. It is further worth noting that certain metals with no

known biologic function in the body can have positive impacts. An example of this is arsenic

trioxide being used to treat acute promyelocytic leukaemia (APL) [6].


11

1.4. Validation of electroanalytical method

1.4.1. Limit of detection (LOD) and limit of quantitation (LOQ)

LOD and LOQ can be defined in many ways. The definition employed herein was based on

the signal to noise ratio in line with the ICH (International Conference on Harmonization of

Technical Requirements for Registration of Pharmaceuticals for Human Use) standards.

- LOD: The lowest amount of the analyte still detected in the sample, but whose

quantitative value cannot be determined with certainty. The LOD is determined when

the signal to noise ratio (S/N) is greater than or equal to 3 [7].

- LOQ: The lowest amount of the analyte still quantified in the sample with a satisfactory

accuracy. The LOQ is determined when the signal to noise ratio is greater than or equal

to 10 [7].

1.4.2. Linearity and calibration curve

The linearity of the method reveals if the measured signal is linearly proportional to the

concentration in a certain range. To determine the linearity, measurements of at least six

concentrations in the defined concentration range need to be carried out [8].

1.4.3. Outliers per Dixon’s and Grubbs’ tests

Data is analysed for outliers when there is a suspicion of errors during the measurements

and that certain measurements need to be excluded. The purpose of identifying outliers is to

assess the measuring process, which is why certain rules need to be followed during this. There

can be several causes for outliers to occur:

- experimental errors,

- errors during measuring,

- outliers can be completely random.

Several standardised tests are used to test outliers [9]. Among the most popular are Dixon’s

test, established by the international standard (ISO 5725-1986(E)), and the newer Grubbs’ test,

established by the international standard (ISO 5725-2:1994(E)). The latter also permits the use

of Dixon’s test [10].

Before the testing can start, all the data is sorted from the smallest to the largest in

accordance to the attribute that is important to us. The null hypothesis H0 in both tests states:

the tested value is an outlier [10].

Dixon’s test:

Another factor that needs to be considered is whether we are testing the maximal or

minimal value for outliers:

Qfor 3-7 objects=𝑥2−𝑥1

𝑥𝑚𝑎𝑥−𝑥1 or Qfor 3-7 objects=

𝑥𝑚𝑎𝑥−𝑥𝑚𝑎𝑥−1

𝑥𝑚𝑎𝑥−𝑥1 (1.1)

Where:

Q Critical value of Dixon’s outlier Test

xmax Outlier with the highest value

x1 Outlier with the lowest value


12

The null hypothesis is confirmed, if Qmeasurement > Qtable, meaning the measurement is an

outlier [10].

Grubbs’ test:

G1one outlier=

−𝑥𝑚𝑖𝑛

𝑠 or G1

one outlier=𝑥𝑚𝑎𝑥−

𝑠 (1.2)

Where:

G Critical value of Grubbs’ outlier test

xmax Outlier with the highest value

xmin Outlier with the lowest value

s Standard deviation

Mean value

The first equation is used when testing the minimal value, and the second equation for testing

the maximal value.

A measurement is an outlier, if G1measurement > Gtable [10].

1.4.4. RSD (relative standard deviation)

RSD (relative standard deviation) reveals, if a “regular” standard deviation is big or small

in comparison to average measurements. A small RSD means that the data is closely gathered

around the average. In contrast, if the RSD is big, the data is more scattered out [11].

𝑅𝑆𝐷 =𝑠

(1.3)

1.5. Scientific background There is only a limited number of scientific articles discussing the topic of the efficiency

and validation of antimony electrodes. Those written mainly include the validation process,

reactions and final efficiency of the electrode. The studies conducted so far have shown that

work with antimony electrodes has provided promising results.

Jovanovski et al. [4] studied an antimony electrode which was, contrary to our experiment,

prepared ex situ for anodic stripping voltammetry (ASV) and adsorptive stripping

voltammetry (AdSV) . Their results have revealed good linearity of the electrode for Cd(II) and

Pb(II) ions in a nondeaerated solution of 0.01 M HCl in the examined concentration range from

25 µg L-1 to 80 µg L-1. They have also revealed the LOD for Cd(II) at 1.1 µg L-1 and 0.3 µg L-1

for Pb(II). The results had an excellent reproducibility. The measurements were conducted at a

deposition potential of -1.0 V for 60 s and an equilibration time of 15 s. A ‘cleaning step’ at a

potential of -0.45 V for 15 s was carried out before any further measurements took place. A

square-wave voltammetric scan was applied at 25 Hz, a potential step of 4 mV and amplitude

of 25 mV [4]. It was concluded that an ex situ prepared antimony film electrode (SbFE) reacts

similarly to an in situ prepared SbFE, as well as similar to electrodes based on bismuth or

mercury while using stripping voltammetry. Its practicality in acidic solutions with pH values

of approx. 2 and in the presence of dissolved oxygen was mentioned as the biggest advantage


13

of SbFE electrodes. Furthermore, the SbFE produced better results, similar to those of mercury

electrodes, regarding hydrogen evolution if compared to bismuth electrodes [4].

Hočevar et al. [12] were the first to introduce an SbFE as a possible alternative for

electrochemical stripping analysis of trace heavy metals. The method they used is similar to the

method used in this thesis. The SbFE was prepared in situ on a glassy carbon substrate electrode

and employed in combination with either ASV or stripping chronopotentiometry (SCP) in

nondeaerated solutions of 0.01 M HCl with a pH value of 2. The parameters under which the

measurements were conducted were furthermore optimised. These include the composition of

the measurement solution, the deposition time and deposition potential. As with the previous

article, the results have shown that the electrode is useful for Cd(II) and Pb(II) analysis with a

minimal effect on the environment. A good linear behaviour was reported in the concentration

range between 20 µg L-1and 140 µg L-1 for both tested ions. The LOD for Cd(II) was at

0.7 µg L-1 and 0.9 µg L-1 for Pb(II) after a 120 s deposition time. RSD was ±3.6 % for Cd(II)

and ±6.2 % for Pb(II) (60 µg L-1). The measurements were conducted at a deposition potential

of -1.2 V and an equilibration time of 15 s. The cleaning step was carried out for 30 s at a

potential of +0.3 V [12]. It was concluded that the electrode produces similar results while

analysing Cd(II) and Pb(II) particles as bismuth and mercury electrodes in combination with

ASV and SCP. The electrode’s results were reproducible. It was also noted that the SbFE

exhibits a very small signal for the reoxidation of antimony and provides markedly lower

background characteristics [12].

1.6. The Hypothesis, purpose and goal of the thesis

The purpose of this thesis is to perform a validation of the SWASV method at different

deposition potentials using antimony film modified glassy carbon electrode (SbFGCE) for

Pb(II) and Cd(II) analysis.


14

2. Analytical method

2.1. Square-wave anodic stripping voltammetry (SWASV) In this work ASV was employed.

ASV is executed in several steps:

1. The electrodeposition step: The metal ion is preconcentrated and deposited on the

electrode as an alloy [13].

2. Equilibration time: The mixing of the solution is turned off after a specific amount

of time has passed. The potential does not change during the equilibration step,

which prevents the reoxidation of the metal [13].

3. Stripping: In the final step, the deposited metal on the electrode begins to oxidise

during the stripping process, transforming it back into its ionic form and thus

removing it from the electrode and back into the solution [13].

Figure 2-1: An example of anodic stripping voltammogram

In combination with ASV, square-wave voltammetry (SWV), also known as square-wave

anodic stripping voltammetry (SWASV) was used. The wave form used in SWV consists of

symmetrical square waves that are superimposed on a staircase waveform. The forward pulse,

which goes in the same direction as the scan, coincides with the staircase step. The reverse pulse

occurs halfway through the staircase step [14].


15

Figure 2-2: (A) potential waveform, (B) one potential cycle, (C) voltammogram in SWV.

The response consists out of a forward (anodic, ψf), backward (cathodic, ψb) and net (ψnet)

component [15].

τ represents time and is used to describe the time needed for one square-wave cycle or one

staircase step in seconds [14]. The height of a single potential step is referred to as square wave

amplitude (Esw) [15]. Two Esw are equal to the peak-to-peak amplitude [14]. Relative to the

direction of the staircase ramp, we can recognise that the pulses with odd serial numbers are

forward pulses and the ones with even serial numbers are backwards pulses. In one cycle, the

reaction on the electrode is driven both in anodic and cathodic directions, thus providing an

insight into the electrode’s mechanism [15]. We can interpret the voltammetric data in terms of

τ, 𝑡p (duration of a single potential pulse 𝑡p = 𝜏2⁄ ), or the frequency of the potential

modulation, which is measured in Hz and defined as 𝑓 = 1𝜏⁄ [14, 15]. The overall modulation

can be represented by the scan rate (υ, defined as 𝜐 = 𝑓 ∆𝐸, ∆𝐸 – step of the staircase) [15].

The current is sampled at the end of each pulse, twice in one cycle. This technique discriminates

against the charging current by delaying the current measured at the end of each pulse [14]. The

forward and backward components are plotted against the potential of the staircase ramp. This

means that for each potential step, two currents are assigned. Further on the forward and

backward currents were substracted of a single potential pulse, obtaining a net current value.

The net currents corresponding to each potential cycle compose the net component of the

square-wave voltammogram [15].


16

3. Experimental

Mesurements were performed with PalmSens EIS3 potentiostat/galvanostat controlled by

the program PSTrace (PalmSens BV, Hauten, Netherlands). The GCE electrode was prepared

before the experiment by polishing it on a polishing cloth (TriDent, PSA, 2.875 in, provided by

Buehler, Lake Bluff, IL, USA) (Figure 3-1) with a thin layer of paste gained by mixing ultrapure

water (Milli-Q, Millipore Corporation, Massachusetts, USA, resistance 18.2 MΩ cm) and

aluminium oxide (0.05 µm, provided by Buehler, Lake Bluff, IL, USA). Afterwards it was

thoroughly washed with ultrapure water. After the entire apparatus was assembled by

connecting the working, counter and reference electrodes with the potentiostat/galvanostat,

20.0 mL of 0.1 M HCl, was poured into the electrochemical cell to clean the electrodes for 900 s

at a potential of +0.6 V. By doing so, possible impurities were oxidized on the electrode, which

consequently diffused into the solution. After cleaning, the electrode was tested via

hexacyanoferrate, in order to determine if it provides the expected reversible response. All

potentials reported herein are vs. Ag/AgCl (KCl saturated) reference electrode.

Figure 3-1: Polishing cloth and the aluminium oxide paste

The electrochemical cell in which the samples were analysed was always thoroughly

cleaned with 0.1 M HCl and ultrapure water. All measurements were carried out in the same

cell under the same laboratory conditions to ensure repeatable testing conditions.

Sb(III) standard solution (1000.0 mg L-1) was provided by Merck KGaA (Darmstadt,

Germany). It was diluted to 500.0 µg L-1 in 0.01 M HCl and used as an electrolyte. All

measurements were performed in a 20.0 mL solution.

Pb(II) and Cd(II) standard solutions (1000.0 mg L-1), provided by Merck KGaA

(Darmstadt, Germany) were used for the metal trace analysis. They were diluted in 0.01 M HCl

as required.

HCl solutions were prepared by diluting a 37 % HCl (provided by Carlo Erba Reagents, Val

de Reuil, France) solution with ultrapure water.

SWASV analysis was performed under the following conditions:

- Conditioning potential: 0.6 V

- Conditioning time: 30 s

- Deposition time: 60 s


17

- Equilibration time: 15 s

- Starting potential: -1.2 V, -1.1 V and -1.0 V

- Final potential: 0.6 V

- Potential step: 0.004 V

- Amplitude: 0.025 V

- Frequency: 25.0 Hz

- Potential standby: 0.6 V

- Standby time: 60 s

3.1. Cyclic voltammetry (CV)

After the cleaning procedure of the working electrode, a test with potassium ferricyanide

was performed. The method in use was cyclic voltammetry (CV), it was needed to check if the

electrode was working properly.

As the potential was sweeped in to the more positive potentials, the Fe(CN)6−3 was

generated from Fe(CN)6−4 as a part of the anodic process. When the potential scan was sweeped

in to the more negative potentials, the latter was produced via a reduction of Fe(CN)6−3. This

was the cathodic process [16].

Anodic peak process: Fe(CN)6−4 → Fe(CN)6

−3 + e-

Cathodic peak process: Fe(CN)6−3 + e- → Fe(CN)6

−4

To check if the GCE electrode is working appropriately, the following analysis was

performed:

- The plot of the peak current (Ip) vs. the square root of the scan rate (𝜐1/2) had to be

linear, to ensure a diffusion controlled electrode reaction [17].

- Value of the peak potential (Ep): because of the fast electron transfer, the 𝐸p value is

independent of the scan rate, indicating a reversible electrode reaction. For that to be

true, the difference between the anodic peak potential (Epa) and the cathodic peak

potential (Epc) must be around 59 mV/n (n is number of electrons) [16, 17].

- The ratio between the anodic current peak (ipa) and cathodic current peak (ipc) is unity

[16].

An example of such analysis is given in Table 3-1.

Table 3-1: Results were similar to the proposed guidelines mentioned above

Scan rate (mV/s) Square root of

the scan rate

Peak potential difference

[∆𝐸p = 𝐸pa−𝐸pc]

Peak current ratio 𝑖pa

𝑖pc

10.00 3.16 0.084 1.08

20.00 4.47 0.076 1.07

50.00 7.07 0.084 1.08

75.00 8.66 0.092 1.08

125.00 11.18 0.100 1.09

150.00 12.25 0.100 1.09

175.00 13.23 0.104 1.09

200.00 14.14 0.108 1.09


18

Figure 3-2: The linear plot of the peak current vs. square root of the scan rate, which

indicates that the reaction is controlled by diffusion.

Figure 3-3: Cyclic voltammogram of potassium ferricyanide, at different scan rates given

in Table 3-1, starting with 10 mV/s and increasing to 200 mV/s.

Increasing

scan rate


19

3.2. Materials

A GCE (glassy carbon electrode, Metrohm AG, type 6.1204.300, Herisau, Switzerland) was

used as the working electrode together with an Ag/AgCl (KCl-saturated, Metrohm AG,

potential compared to standard hydrogen electrode (SHE) is 0.197 V, at 25°C) as a reference

electrode, and platinum wire (Metrohm AG) as a counter electrode. All glassware was provided

by Metrohm.


20

4. Results and discussion

4.1. LOD and LOQ analysis The experiments were conducted at three deposition potentials: -1.2 V, -1.1 V and -1.0 V

vs. Ag/AgCl.

After several cleaning repetitions of the electrochemical cell, replacements of the working,

reference and counter electrodes with identical newer ones, repeated preparation of all

chemicals and replacement of the glassware, the signal for both heavy metal ions in the blank

solution was still significant. This is shown in Figure 4-1.

Figure 4-1: The reduction peaks for Cd(II) (at -0.75 V) and Pb(II) (at -0.36 V)in the blank

0.01 M HCl solution using different deposition potentials: -1.0 V (blue curve), -1.1 V (red

curve) and -1.2 V (green curve).

The first suspicion was that the ultrapure water was contaminated, so the HPLC-grade water

(Sigma-Aldrich, St. Louis, Missouri, USA) was used for both cleaning and preparing a new

solution instead, but the signals for Cd(II) and Pb(II) in the blank solution remained unchanged.

Another reason for such an occurrence could have been the presence of heavy metals in the

acid, therefore we used ultrapure HCl acid to prepare solutions (34 %-37 %, Carlo Erba

Reagents, Milano, Italy) instead. The results with ultrapure HCl acid are presented in

Figure 4-2.


21

Figure 4-2: The reduction peaks for Cd(II) (at -0.75 V) and Pb(II) (at -0.33 V) in the blank

solution in ultrapure HCl acid using different deposition potentials: : -1.0 V (blue

curve), -1.1 V (red curve) and -1.2 V (green curve).

When using the ultrapure HCl acid, the reduction peaks for both metal ions in blank

solution barely changed and were still significant, thus concluding that the LOD and LOQ could

not be determined with sufficient certainty and are therefore not reported herein. However,

LOQ is certainly at a lower concentration than 14.6 µg L-1 which is the lowest concentration

limit employed for linear calibration plot.


22

4.2. Linearity

Figure 4-3 shows current vs. γ response in the concentration range from 1.0 µg L-1 to

106.3 µg L-1 for Pb(II).

Figure 4-3: Concentration range for Pb(II) from 1.0 µg L-1 to 106.3 µg L-1. Points

represent values at different deposition potentials, blue at -1.2 V, orange at -1.1 V and gray at

-1.0 V.

Figure 4-4 shows current vs. γ response in the concentration range from 1.0 µg L-1 to

106.3 µg L-1 for Cd(II).

Figure 4-4: Concentration range for Cd(II) from 1.0 µg L-1 to 106.3 µg L-1. Points

represent values at different deposition potentials, blue at -1.2 V, orange at -1.1 V and gray at

-1.0 V.


23

The method is linear for both Cd(II) (Figures 4-5 through 4-7) and Pb(II) (Figures 4-8

through 4-10) in the concentration range from 14.6 µg L-1 to 100.0 µg L-1. R2 greater than 0.98

was employed as a validation protocol.



are given in Table 4-1.

Table 4-1: Linearity regression analysis of Cd(II) plot at a -1.2 V deposition potential for all three curves.

Date and line color Linear correlation Correlation coefficient

31.3.2017 (grey line) y = 0.1313x - 1.0718 R² = 0.99

13.4.2017 (blue line) y = 0.1235x - 0.5653 R² = 0.99

24.4.2017 (orange line) y = 0.1589x - 0.3841 R² = 0.99





24



31.3.2017 (grey line) y = 0.1527x - 1.3477 R² = 0.99

13.4.2017 (blue line) y = 0.1509x - 0.9431 R² = 0.98

24.4.2017 (orange line) y = 0.1874x - 0.9620 R² = 0.99






31.3.2017 (grey line) y = 0.1644x - 2.0007 R² = 0.99

13.4.2017 (blue line) y = 0.1638x - 1.8404 R² = 0.99

24.4.2017 (orange line) y = 0.1963x - 1.7567 R² = 0.99


25



given in Table 4-4.

Table 4-4: Linearity regression analysis of Pb(II) plot at a -1.2 V deposition potential for both curves.


13.4.2017 (blue line) y = 0.133x - 1.6801 R² = 0.99

24.4.2017 (orange line) y = 0.1514x - 1.3826 R² = 0.99



given in Table 4-5.



13.4.2017 (blue line) y = 0.1417x - 1.7109 R² = 0.99

24.4.2017 (orange line) y = 0.1563x - 1.6190 R² = 0.99


26



given in Table 4-6.



13.4.2017 (blue line) y = 0.1283x - 1.6526 R² = 0.99

24.4.2017 (orange line) y = 0.1388x - 1.6768 R² = 0.99

4.3. Accuracy

The accuracy was tested for 4 different concentrations, i.e. 15.0 µg L-1, 25.0 µg L-1,

30.0 µg L-1, 40.0 µg L-1, at three deposition potentials. The concentration of Cd(II) and Pb(II)

was determined using the calibration curve.

Average recovery was calculated in two steps:

- First step: Recovery = 𝛾𝑑𝑒𝑡𝑒𝑟𝑚𝑖𝑛𝑒𝑑

𝛾𝑡ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 (4.1)

Where:

γ mass concentration

- Second step: average recovery = 1

𝑛∑ 𝑎𝑖

𝑛𝑖=1 (a1+a2+a3+…+an) (4.2)

Where:

n number of measurement

a sample

∑ sum

Calibration curves in use are shown in Figures 4-11 through 4-16.


27

Figure 4-11: Calibration curve for Cd(II) at a deposition potential of -1.2 V.



28


Figure 4-14: Calibration curve for Pb(II) at a deposition potential of -1.2 V.



29


Tables from 4-7 to 4-10, show the results for accuracy (recovery) and corresponding RSD.

Table 4-7: Recovery determined for concentration at 15.0 µg L-1

Measurement Deposition

potential Recovery Pb(II) [%] Recovery Cd(II) [%]

1

-1.2 V 113.86 73.26

-1.1 V 119.29 81.99

-1.0 V 120.20 97.18

2

-1.2 V 111.18 114.45

-1.1 V 113.39 113.05

-1.0 V 118.20 126.60

3

-1.2 V 104.06 107.02

-1.1 V 106.39 106.35

-1.0 V 100.03 111.41

4

-1.2 V 106.02 113.19

-1.1 V 104.32 106.51

-1.0 V 106.33 119.75

5

-1.2 V 122.59 123.80

-1.1 V 125.20 122.44

-1.0 V 131.43 124.09

6

-1.2 V 108.43 96.41

-1.1 V 115.85 96.72

-1.0 V 111.49 101.68

Average recovery Pb(II)

[%]

Average recovery Cd(II)

[%]

-1.2 V 111.02 104.69

-1.1 V 114.07 104.51

-1.0 V 114.61 113.45

RSD [%]


30

-1.2 V 6.00 17.06

-1.1 V 6.89 13.32

-1.0 V 9.70 10.67



potential Recovery Pb(II) Recovery Cd(II)

1

-1.2 V 93.93 109.49

-1.1 V 81.89 105.35

-1.0 V 79.91 116.84

2

-1.2 V 97.53 121.62

-1.1 V 91.00 109.19

-1.0 V 85.62 122.91

3

-1.2 V 86.47 113.72

-1.1 V 81.65 104.46

-1.0 V 75.77 107.68

4

-1.2 V 87.22 100.53

-1.1 V 82.32 96.52

-1.0 V 79.25 109.02

5

-1.2 V 90.78 89.89

-1.1 V 88.68 86.88

-1.0 V 93.06 93.77

Average recovery Pb(II) Average recovery Cd(II)

-1.2 V 91.19 107.05

-1.1 V 85.11 100.48

-1.0 V 82.72 110.04

RSD [%]

-1.2 V 5.08 11.44

-1.1 V 5.17 8.85

-1.0 V 8.19 9.99



potential Recovery Pb(II) Recovery Cd(II)

1

-1.2 V 100.13 97.36

-1.1 V 97.24* 93.11

-1.0 V 89.88 99.37

2

-1.2 V 117.18 120.26

-1.1 V 115.96 111.74

-1.0 V 88.09 102.01

3

-1.2 V 107.25 106.93

-1.1 V 119.27 106.09

-1.0 V 108.90 121.43

4

-1.2 V 130.40 132.94

-1.1 V 118.97 126.36

-1.0 V 106.17 132.64


31

5

-1.2 V 117.07 127.93

-1.1 V 112.98 121.16

-1.0 V 92.38 131.51

6

-1.2 V 141.20 138.54

-1.1 V 121.31 127.42

-1.0 V 93.06 138.95


-1.2 V 118.87 120.66

-1.1 V 117.70 114.32

-1.0 V 96.41 120.99

RSD [%]

-1.2 V 12.60 13.13

-1.1 V 2.80 11.65

-1.0 V 9.20 13.82

*Outlier according to Grubbs’ and Dixon’s test



potential RecoveryPb(II) Recovery Cd(II)

1

-1.2 V 115.29 101.58

-1.1 V 103.58 96.71

-1.0 V 84.90 102.75

2

-1.2 V 105.07 95.98

-1.1 V 93.36 90.65

-1.0 V 83.69 98.71

3

-1.2 V 130.05 118.67

-1.1 V 108.66 113.65

-1.0 V 81.47 123.90

4

-1.2 V 96.42 104.91

-1.1 V 90.79 98.45

-1.0 V 71.65 107.74

5

-1.2 V 99.64 106.94

-1.1 V 94.12 101.93

-1.0 V 73.92 112.62

6

-1.2 V 91.83 99.79

-1.1 V 85.86 95.78

-1.0 V 79.17 113.33


-1.2 V 106.38 105.26

-1.1 V 96.06 100.09


32

-1.0 V 79.13 111.26

RSD [%]

-1.2 V 13.28 7.53

-1.1 V 8.81 7.88

-1.0 V 6.75 8.10

The data in the Tables 4-7 through 4-10 confirms that the tested method is both accurate

and precise.

All RSD values are below the prescribed 20% value, proving the method’s precision [18].

The accuracy was proven via average recovery, which was mainly in the limits, between 80%

and 120% [18], except for Cd(II) at deposition potentials of -1.0 V and -1.2 V at 40.0 µg L-1

and Pb(II) at the deposition potential of -1.0 V also at 40.0 µg L-1. When testing the method for

outliers, only one such measurement was found for Pb(II) at the deposition potential of -1.1 V

at the concentration of 30.0 µg L-1. The data shows that the method works best when used with

the deposition potential -1.1 V for both Pb(II) and Cd(II).


33

5. Conclusion

This work presents the validation of the SWASV technique with a glassy carbon electrode

modified with antimony film for trace metal analysis. Antimony film was prepared in situ. This

method showed good electroanalytical performance for Cd(II) and Pb(II) trace analysis.

It was determined that the method is linear in the concentration range from 14.6 µg L-1 to

100.0 µg L-1 for simultaneous analysis of both Pb(II) and Cd(II). The limit of detection and the

limit of quantification were not determined, due to HCl solution impurity.

The accuracy of the method was tested for four different concentrations, i.e. 15.0 µg L-1,

25.0 µg L-1, 30.0 µg L-1 and 40.0 µg L-1. It was found out that the average recovery values for

all three deposition potentials, excluding Cd(II) at deposition potentials of -1.0 V and -1.2 V at

40.0 µg L-1 and Pb(II) at the deposition potential of -1.0 V also at 40.0 µg L-1, were within the

prescribed interval (between 80 % and 120 %), thus proving the method as accurate. All RSD

values were under the limit of 20 %, thus indicating that the method is precise. The gathered

data shows, that the method works best when used with the deposition potential -1.1 V vs.

Ag/AgCl for both Pb(II) and Cd(II)

To conclude, the method using SbFE, as it stands today, is very useful for the detection and

measurements of trace Cd(II) and Pb(II) in acidic solutions. With further research and

optimisation it will become an even better alternative to the standard mercury electrode and will

stand on par with the bismuth electrode. In the future, however, more research needs to be done

on other electrodes, using elements such as copper to broaden the range of potential electrodes

that will be able to replace the mercury electrode once and for all.


34

6. References

1. BV, L. Heavy Metals. Access date: 20.6.2017]; Available from:

http://www.lenntech.com/processes/heavy/heavy-metals/heavy-metals.htm.

2. Kibria, G., Trace/heavy Metals and Its Impact on Environment, Biodiversity and

Human Health- A Short Review. 2014.

3. Pujol, L., et al., Electrochemical sensors and devices for heavy metals assay in water:

the French groups' contribution. Frontiers in Chemistry, 2014. 2: p. 19.

4. Jovanovski, V., S.B. Hocevar, and B. Ogorevc, Ex Situ Prepared Antimony Film

Electrode for Electrochemical Stripping Measurement of Heavy Metal Ions.

Electroanalysis, 2009. 21(21): p. 2321-2324.

5. Tchounwou, P.B., et al., Heavy Metals Toxicity and the Environment. EXS, 2012. 101:

p. 133-164.

6. Singh, R., et al., Heavy metals and living systems: An overview. Indian Journal of

Pharmacology, 2011. 43(3): p. 246-253.

7. farmacijo, U.v.L.F.z. SIGNALI- tipi analiznih metod. Access date: 22.7.2017];

Available from: http://www.ffa.uni-

lj.si/fileadmin/homedirs/11/Predmeti/IFA/IFA1_signali_.pdf.

8. Trbojević, J., Določanje železa z atomsko absorpcijsko spektrometrijo (validacija

metode). 2016. p. 47.

9. Marr, P. Outlier Detection. Access date: 10.8.2017]; Available from:

http://webspace.ship.edu/pgmarr/Geo441/Lectures/OPT%201%20-

%20Outlier%20Detection.pdf.

10. Zupan, J., Kemometrija in obdelava eksperimentalnih podatkov. 2009, Ljubljana,

Slovenija: Inštitut nove revije, zavod za humanistiko in Kemijski inštitut.

11. StatisticHowTo. Relative Standard Deviation: Definition & Formula. Access

date: 17.7.2017]; Available from: http://www.statisticshowto.com/relative-standard-

deviation/.

12. Hocevar, S.B., et al., Antimony Film Electrode for Electrochemical Stripping Analysis.

Analytical Chemistry, 2007. 79(22): p. 8639-8643.

13. Tel Aviv University, L.i.E. Stripping Voltammetry. Access date: 20.6.2017]; Available

from: https://www.tau.ac.il/~advanal/StrippingVoltammetry.htm.

14. Research, P.A. Application Note S-7, Square wave Voltammetry. Access

date: 24.6.2017]; Available from: http://www.ameteksi.com/-

/media/ameteksi/download_links/documentations/library/princetonappliedresearch/ap

plication_note_s-7.pdf?la=en.

15. Mirceski, V., et al., Square-Wave Voltammetry: A Review on the Recent Progress.

Electroanalysis, 2013. 25(11): p. 2411-2422.

16. Marasinghe, A. Cyclic Voltammetric Study of ferrocyanide/ferricyanide Redox

Couple. Access date: 20.8.2017]; Available from:

http://web.mnstate.edu/marasing/CHEM480/labls/LABS/CV/Cyclic%20voltammetric

%20study%20of%20ferrocyanide_ferricyanide%20redox%20couple.pdf.

17. Library, A.S.D. Experiments in Analytical Electrochemistry. Access date: 2.7.2017];

Available from: http://www.asdlib.org/onlineArticles/elabware/kuwanaEC_lab/PDF-

19-Experiment1.pdf.

18. Crime, L.a.S.S.o.U.N.O.o.D.a. Guidance for the Validation of Analytical Methodology

and Calibration of Equipment used for Testing of Illicit Drugs in Seized Materials and

Biological Specimens. 2009 Access date: 20.6.2017]; Available from:

https://www.unodc.org/documents/scientific/validation_E.pdf.

http://www.lenntech.com/processes/heavy/heavy-metals/heavy-metals.htm

http://www.ffa.uni-lj.si/fileadmin/homedirs/11/Predmeti/IFA/IFA1_signali_.pdf

http://www.ffa.uni-lj.si/fileadmin/homedirs/11/Predmeti/IFA/IFA1_signali_.pdf

http://webspace.ship.edu/pgmarr/Geo441/Lectures/OPT%201%20-%20Outlier%20Detection.pdf

http://webspace.ship.edu/pgmarr/Geo441/Lectures/OPT%201%20-%20Outlier%20Detection.pdf

http://www.statisticshowto.com/relative-standard-deviation/

http://www.statisticshowto.com/relative-standard-deviation/

https://www.tau.ac.il/~advanal/StrippingVoltammetry.htm

http://www.ameteksi.com/-/media/ameteksi/download_links/documentations/library/princetonappliedresearch/application_note_s-7.pdf?la=en



http://web.mnstate.edu/marasing/CHEM480/labls/LABS/CV/Cyclic%20voltammetric%20study%20of%20ferrocyanide_ferricyanide%20redox%20couple.pdf

http://web.mnstate.edu/marasing/CHEM480/labls/LABS/CV/Cyclic%20voltammetric%20study%20of%20ferrocyanide_ferricyanide%20redox%20couple.pdf

http://www.asdlib.org/onlineArticles/elabware/kuwanaEC_lab/PDF-19-Experiment1.pdf

http://www.asdlib.org/onlineArticles/elabware/kuwanaEC_lab/PDF-19-Experiment1.pdf

https://www.unodc.org/documents/scientific/validation_E.pdf


35

7. Življenjepis (CV)

Aljaž Ramot

Ciril-Metodov drevored 5, 2250 Ptuj

E-MAIL: [email protected] GSM: +38631-311-250

Kratek opis:

Star sem 22let. Sem komunikativen, socialen in vedno željan novih izkušenj, ter izzivov. Poglabljam se predvsem v

področje znanosti, komunikacij in novih tehnologij, s katerimi sem rad na tekočem. Večkrat sem se srečal tudi z javnim

nastopanjem, tako v sklopu izobraževanja kot tudi izven. Opravljeno imam gimnazijsko maturo z odličnim uspehom,

trenutno pa študiram kemijsko tehnologijo na Univerzi v Mariboru.

S področja kemije in kemijske analitike imam že nekaj izkušenj. Z delom v tej smeri sem pričel z raziskovalno nalogo

v srednji šoli, nadaljeval s fakultativnim izobraževanjem, prakso in delom za diplomsko nalogo.

Izkušnje imam tudi iz področja dela z ljudmi, saj 4 leta delam kot cestninski blagajnik pri podjetju DARS,

preko študentske napotnice.

eleno delovno mesto:

Želim si delovnega mesta, kjer bom lahko širil svoj spekter znanj, spoznaval nove tehnologije in se udejanjil v najboljši meri.

Sam sem prilagodljiv, zato mi delo v kolektivu ne povzroča nevšečnosti. Sem organiziran, zato mi tudi večji obseg delovnih

nalog ne predstavlja težav.

Delovne izkušnje

Raziskovalno

delo

Prve izkušnje na področju raziskovalnega dela, sem pridobil v srednji šoli, ko sem s pomočjo

raziskovalne naloge, Meritve koncentracij in velikosti nanodelcev na Gimnaziji Ptuj, spoznal

kemijsko analizo in osvojil zlato priznanje Zveze za tehnično kulturo Slovenije (ZOTKS).

V času študija sem sodeloval pri projektu Inovativne analize genoma in biooznačevalcev za

boljše diagnosticiranje in zdravljenje bolnikov s kroničnimi vnetnimi črevesnimi boleznimi

(GenBioKVČB), ki je potekal v sodelovanju z Medicinsko fakulteto Univerze v Mariboru.

Praktično

usposabljanje

V sklopu predmeta na fakulteti, sem opravljal praktično usposabljanje v podjetju Talum inštitut

d.o.o. Tam sem se srečal s številnimi tehnikami analize vod, odpadkov in plinov.

Diplomsko delo V sklopu diplomskega dela, validacija elektroanalizne metode z antimonovo elektrodo za

analizo težkih kovin v sledovih, sem opravljal analize in se spoznal s programom PSTrace.


36

Moje osrednje lastnosti: Komunikativnost, organiziranost, odgovornost, samoiniciativnost, sposobnost dela v kolektivu, retorične sposobnosti,

iznajdljivost, poštenost, vztrajnost

Kronološki pregled dosedanjih delovnih mest: 2013 - 2017 Dars d.d.

Cestninski blagajnik

5.2017 – 9.2017 Vitiva d.d.

Pomoč pri vzdrževanju

Izobrazba

2009 – 2013 Gimnazija Ptuj

2013 – 2017

2017- predvidoma

2019

Univerza v Mariboru,

Smer: Kemijska tehnologija (VS)

Univerza v Mariboru

Smer: Kemijska tehnika

Dodatna izobraževanja

2012 - 2013 Deutsche Sprachdiplom

2010, 2011, 2012 English camp (Društvo več)

Druga znanja in veščine

Tuji jeziki: Angleščina (razumevanje: odlično, branje: odlično, pisanje: odlično)

Nemščina (razumevanje: odlično, branje: odlično, pisanje: dobro)

Hrvaščina (razumevanje: odlično, branje: odlično, pisanje: dobro)

Delo z računalnikom: Okolje Windows, MS Office (Word, Excel, PowerPoint, Paint) (poznavanje: odlično,

uporaba: vsak dan)

Google Documents (poznavanje: odlično, uporaba: večkrat tedensko)

PSTrace (poznavanje: dobro, uporaba: v času diplomskega dela)

Cubase (poznavanje: dobro, uporaba: občasno)

Videopad (poznavanje: dobro, uporaba: občasno)

AutoCAD (poznavanje: osnovno, uporaba: občasno)

Hobiji: Atletika, montaža audi in video posnetkov, v prostem času igram v glasbeni skupini

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