Influence of Water on the Property Values of Certified ... · Workshop on water in food - 30th of...

Institute for Reference Materials and Measurements (IRMM)Geel, Belgium

http://www.irmm.jrc.behttp://www.jrc.cec.eu.int

Workshop on water in food - 30th of March 2004 - Influence of water on the property values of CRMs - Seyhan Yazgan - 1

Influence of Water on the Property Values of Certified Reference Materials

Seyhan Yazgan, Alexander Bernreuther, Franz Ulberth, Heinz-Dieter Isengard


Content

• Introduction

• Certified Reference Materials (CRMs)

• Influence of water on the assigned value

• Comparison of different methods for water/moisture determination

• TG-MS analysis

• Kinetic analysis

• Conclusions


Certified Reference Materials (CRMs)BCR-517 FULL FAT SOYA (dietary fibre)BCR-518 BRAN BREAKFAST CEREAL (dietary fibre)BCR-519 ANHYDROUS BUTTER FAT (triglycerides)BCR-522 BOVINE BLOOD LYSATE (haemiglobincyanide)BCR-524 INDUSTRIAL SOIL (PAH's)BCR-528 BACILLUS CEREUS (number of colony forming particles)BCR-529 INDUSTRIAL SANDY SOIL (PCDD's, PCDF's)BCR-530 INDUSTRIAL CLAY SOIL (PCDD's, PCDF's)BCR-532 (RM) UNSPIKED MILK POWDER (PCDD, PCDF blank)BCR-533 (RM) SPIKED MILK POWDER (PCDD's, PCDF's, low level)BCR-535 FRESHWATER HARBOUR SEDIMENT (PAH's)BCR-536 FRESHWATER HARBOUR SEDIMENT (PCB's)BCR-537 PLASTIC FILM (OVERALL MIGRATION IN OLIVE OIL (film A)BCR-542 MUSSEL (dc-saxitoxin)BCR-544 LYOPHYLISED CHROMIUM SOLUTION (Cr III, Cr VI)BCR-545 WELDING DUST LOADED ON FILTER (Cr VI, Cr)BCR-547 ACETALDEHYDE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-549 ACETONE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-551-2 2,4-DINITROPHENYLHYDRAZONES in ACETONITRILEBCR-555 CHLORINATED HYDROCARBONS ON TENAXBCR-562 AROMATIC HYDROCARBONS ON CHARCOALBCR-563 COMMON WHEAT FLOUR (properties)BCR-564 SiO2/Si (10,50,120 nm)BCR-577 HUMAN SERUM (17 ß-ESTRADIOL, medium level)BCR-578 HUMAN SERUM (17 ß-ESTRADIOL, high level)BCR-579 COASTAL SEAWATER (Hg)BCR-580 ESTUARINE SEDIMENT (Hg, methylmercury)BCR-642 HUMAN URINE (As, Cd, Cr, Co and 1-hydroxypyrene)BCR-645 ARTIFICIAL FOODSTUFF (Free sugars and starch/gluchose)BCR-647 HUMAN ADENOSINE DEAMINASE (ADA 1)BCR-648-9 BOVINE LIVERBCR-651 BEER (EtOH, low level)

BCR-605 URBAN DUST (trimethyllead)BCR-607 MILK POWDER (PCDD's, PCDF's)BCR-609 GROUND WATER (trace elements, low level)BCR-626 ARSENOBETAINE STANDARD SOLUTIONBCR-627 TUNA FISH TISSUE (As species)BCR-628 ABNORMAL REFERENCE PLASMA-2 for prothrombin timeBCR-629 EUROPEAN REFERENCE PLASMA for Factor VIIIBCR-653 WINE (EtOH, low level)BCR-656 ABSOLUTE ALCOHOLBCR-657 GLUCOSEBCR-658 SYNTHETIC WINEBCR-715 WASTEWATER (INDUSTRIAL EFFLUENT) (trace elements)BCR-716 MAIZE (very low level ZON)BCR-717 MAIZE (low level ZON)BCR-718 CANNED FRESH HERRINGBCR-719 CANNED FRESH CHUBBCR-720 FLOUNDER BILE (PAHs)BCR-721 PLAICE BILE (PAHs)IRMM-410S-0 GENETICALLY MODIFIED SOYA BEANS (0 % RR)IRMM-411R-0 GENETICALLY MODIFIED Bt-176 MAIZE (0 %)IRMM-413-1 GENETICALLY MODIFIED MON810 MAIZE (0.1 %)IRMM-440 RESIN-BONDED FIBRE BOARD (thermal conductivity)IRMM-441 n-HEPTANE (purity)IRMM-442 ISOOCTANE (purity)IRMM-443-1 EUROSOIL (adsorption coefficients and pH)IRMM-444 Pork fat (PCB blank)IRMM-445 Pork fat (very low PCB level)IRMM-446 Pork fat (low PCB level)IRMM/IFCC-451 CORTISOL REFERENCE SERUM PANELIRMM-502A 237NpO2 (0.5 mm spheres)IRMM-534C Al-2.0 % Sc (1.0 mm wire)

BCR-517 FULL FAT SOYA (dietary fibre)BCR-518 BRAN BREAKFAST CEREAL (dietary fibre)BCR-519 ANHYDROUS BUTTER FAT (triglycerides)BCR-522 BOVINE BLOOD LYSATE (haemiglobincyanide)BCR-524 INDUSTRIAL SOIL (PAH's)BCR-528 BACILLUS CEREUS (number of colony forming particles)BCR-529 INDUSTRIAL SANDY SOIL (PCDD's, PCDF's)BCR-530 INDUSTRIAL CLAY SOIL (PCDD's, PCDF's)BCR-532 (RM) UNSPIKED MILK POWDER (PCDD, PCDF blank)BCR-533 (RM) SPIKED MILK POWDER (PCDD's, PCDF's, low level)BCR-535 FRESHWATER HARBOUR SEDIMENT (PAH's)BCR-536 FRESHWATER HARBOUR SEDIMENT (PCB's)BCR-537 PLASTIC FILM (OVERALL MIGRATION IN OLIVE OIL (film A)BCR-542 MUSSEL (dc-saxitoxin)BCR-544 LYOPHYLISED CHROMIUM SOLUTION (Cr III, Cr VI)BCR-545 WELDING DUST LOADED ON FILTER (Cr VI, Cr)BCR-547 ACETALDEHYDE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-549 ACETONE-2,4-DINITROPHENYLHYDRAZONE (purity)BCR-551-2 2,4-DINITROPHENYLHYDRAZONES in ACETONITRILEBCR-555 CHLORINATED HYDROCARBONS ON TENAXBCR-562 AROMATIC HYDROCARBONS ON CHARCOALBCR-563 COMMON WHEAT FLOUR (properties)BCR-564 SiO2/Si (10,50,120 nm)BCR-577 HUMAN SERUM (17 ß-ESTRADIOL, medium level)BCR-578 HUMAN SERUM (17 ß-ESTRADIOL, high level)BCR-579 COASTAL SEAWATER (Hg)BCR-580 ESTUARINE SEDIMENT (Hg, methylmercury)BCR-642 HUMAN URINE (As, Cd, Cr, Co and 1-hydroxypyrene)BCR-645 ARTIFICIAL FOODSTUFF (Free sugars and starch/gluchose)BCR-647 HUMAN ADENOSINE DEAMINASE (ADA 1)BCR-648-9 BOVINE LIVERBCR-651 BEER (EtOH, low level)

BCR-605 URBAN DUST (trimethyllead)BCR-607 MILK POWDER (PCDD's, PCDF's)BCR-609 GROUND WATER (trace elements, low level)BCR-626 ARSENOBETAINE STANDARD SOLUTIONBCR-627 TUNA FISH TISSUE (As species)BCR-628 ABNORMAL REFERENCE PLASMA-2 for prothrombin timeBCR-629 EUROPEAN REFERENCE PLASMA for Factor VIIIBCR-653 WINE (EtOH, low level)BCR-656 ABSOLUTE ALCOHOLBCR-657 GLUCOSEBCR-658 SYNTHETIC WINEBCR-715 WASTEWATER (INDUSTRIAL EFFLUENT) (trace elements)BCR-716 MAIZE (very low level ZON)BCR-717 MAIZE (low level ZON)BCR-718 CANNED FRESH HERRINGBCR-719 CANNED FRESH CHUBBCR-720 FLOUNDER BILE (PAHs)BCR-721 PLAICE BILE (PAHs)IRMM-410S-0 GENETICALLY MODIFIED SOYA BEANS (0 % RR)IRMM-411R-0 GENETICALLY MODIFIED Bt-176 MAIZE (0 %)IRMM-413-1 GENETICALLY MODIFIED MON810 MAIZE (0.1 %)IRMM-440 RESIN-BONDED FIBRE BOARD (thermal conductivity)IRMM-441 n-HEPTANE (purity)IRMM-442 ISOOCTANE (purity)IRMM-443-1 EUROSOIL (adsorption coefficients and pH)IRMM-444 Pork fat (PCB blank)IRMM-445 Pork fat (very low PCB level)IRMM-446 Pork fat (low PCB level)IRMM/IFCC-451 CORTISOL REFERENCE SERUM PANELIRMM-502A 237NpO2 (0.5 mm spheres)IRMM-534C Al-2.0 % Sc (1.0 mm wire)

• Calibration • Method validation• Quality control

CRMs are used for


Interlaboratory comparison

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

wat

er c

on

ten

t

%

-100

-80

-60

-40

-20

0

20

40

60

80

100

Dev

iati

on

fro

m t

he

KF

-tit

rati

on

val

ue

in %

below 80 deg C 80-85 deg C 100-102 deg C 103-105 deg C 106-120 deg C 130 deg C

Results for water content on the non-equilibrated CTS as reported by IMEP-19 participants using drying-oven method according to applied drying temperature

IMEP- 19: Trace elements in Rice water content (Karl Fischer Titration) : 4.53 ± 0.22 % [U =k ·u c (k =1)]

1 valueabove 100%


1.52

1.54

1.56

1.58

1.60

1.62

1.64

1.66

1.68

1.70

1.72

0.53 1.53 2.53 3.53 4.53 5.53 6.53 7.53

water content in %

corr

ecte

d va

lue

in m

g/kg

Example for the influence of the water content on the assigned value

Analyte: CadmiumMaterial: rice flour (IRMM-804)

assigned value:1.618 mg/kg ± 0.028 mg/kg

1.5851.601

1.671

1.653

1.635

1.569


Comparison drying oven - KFT

Analysed CRMs: • BCR-380R whole milk powder• BCR-685 skimmed milk powder• IRMM-804 rice flour • BCR-679 cabbage powder • BCR-515 dried carrot • BCR-431 Brussels sprouts • BCR-485 mixed vegetables • BCR-516 dried apple

Methods:• Volumetric Karl-Fischer titration• Drying oven(102 °C ± 2 °C, for 2 h [IDF 26 A: 1993 for milk powder])


Results

02468

10121416

BCR-

380R

whol

e m

ilkpo

wder

BCR-

685

skim

med

milk

powd

er

IRM

M-8

04ric

e flo

ur

BCR-

679

cabb

age

powd

er

BCR-

516

drie

d ap

ple

BCR-

515

drie

d ca

rrot

BCR-

485

mix

edve

geta

bles

BCR-

431

Brus

sels

spro

utsm

oist

ure/

wate

r con

tent

in %

drying oven 120 min at 102 °C KFT (minimum extraction time: 3 min at 40 °C)


TG - MS


BCR-685 skimmed milk powder

H2O

temperature

mass loss


BCR-679 cabbage powder

H2O

temperature

mass loss

CO2


Whole milk powder (BCR-380R) over saturated solutions

TG Analysis

• Temperature scanning rate: 10 °C/min• 20 to 180 °C

potassium sulfate sodium chloride magnesium nitrate lithium chloride molecular sievetheor. aw 0.936 0.753 0.529 0.113 --

Sample preparation: 7 days in desiccators over different saturated salt solutions

Water content in %K2SO4 NaCl Mg(NO3)2 LiCl molecular sieve from bottle

n 6 6 6 6 6 6mean 14.60 8.41 5.26 3.20 0.80 3.37

SD 0.24 0.11 0.14 0.38 0.10 0.05RSD in % 1.65 1.25 2.65 11.90 12.26 1.44


TG - BCR-380 whole milk powder

-16

-14

-12

-10

-8

-6

-4

-2

0

20 15 30 45 60 75 90 105 120 135 150 165 180 195

temperature in °C

wei

gh

t lo

ss in

%14.60 8.41 5.26 3.20 0.80 3.37water content in %

free water

crystal water

decomposition

Temperature scanning rate: 10 °C/min


DTG - BCR-380 whole milk powder

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

15 35 55 75 95 115 135 155 175 195

temperature in °C

DT

G in

°C

/min

14.60 8.41 5.26 3.20 0.80 3.37water content in %:

Temperature scanning rate: 10 °C/min

free water

crystal water

decomposition

DTG

in %

/min


Kinetic analysis

Analysed food components:

• Pectin, esterification degree (ED): 94 %• Pectin, esterification degree (ED): 65 %• Pectin, esterification degree (ED): 25 %• Starch, 73 % amylopectin (AP), 27 % amylose• Starch, 100 % amylopectin (AP)• Gelatine 75 Bloom• Gelatine 225 Bloom• Cellulose microgranular• Cellulose fibrous medium• Cellulose fibrous long• Casein

• Before- mentioned CRMs


Moisture sorption analyser


• Relative humidity (RH) step 15 % to 80 %• Constant temperature of 25 °C


0

5

10

15

20

25

0 20 40 60 80 100 120 140 160time

wei

ght i

n %

skimmed milk powder

gelatine 75 Bloom

casein

starch

pectin 25 % ED

rice flour

whole milk powder

pectin 65 % ED

pectin 94 % ED

cellulose

gelatine 225 Bloom

time in s

wei

ght g

ain

in %

Water uptake kinetic of different food models and CRMs

Humidity step: 15 % to 80 %Temperature: 25 °C


))exp(1()( BtAtm ⋅−−⋅=

stretched-exponential model

Pectin, esterification degree: 25 %-5

0

5

10

15

20

25

30

0 20 40 60 80 100 120 140

time

wat

er u

pta

ke in

%

water uptake exponential model


Factor A

0

5

10

15

20

25

30

35

Pectin

94%

Pectin

65%

Pectin

25%

Starch

73% AP

Starch

100%

AP

Gelatin

e 75B

loom

Gelatin

e 225

Bloom

Cellulos

e micr

ogran

ular

Cellulos

e fibr

ous m

edium

Cellulos

e fibr

ous lo

ng Casein

IRMM-804 r

ice flo

ur

BCR-685 s

kimmed

milk

powde

r

BCR-380R

whole m

ilk po

wder

BCR-516 d

ried a

pple

BCR-515 D

ried C

arrot

BCR-431 B

russe

ls spro

uts

BCR-485 M

ixed v

egeta

bles

BCR-679 c

abba

ge po

wder


Factor B

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0.20

Pectin

94%

Pectin

65%

Pectin

25%

Starch

73% AP

Starch

100%

AP

Gelatin

e 75B

loom

Gelatin

e 225

Bloom

Cellulos

e micr

ogran

ular

Cellulos

e fibr

ous m

edium

Cellulos

e fibr

ous lo

ng Casein

IRMM-804 r

ice flo

ur

BCR-685 s

kimmed

milk

powde

r

BCR-380R

whole m

ilk po

wder

BCR-516 d

ried a

pple

BCR-515 D

ried C

arrot

BCR-431 B

russe

ls spro

uts

BCR-485 M

ixed v

egeta

bles

BCR-679 c

abba

ge po

wder


-5

0

5

10

15

20

25

0 20 40 60 80 100 120 140

time

wat

eru

pta

ke in

%

Pectin, ED: 94% Pectin, ED: 65% Pectin, ED: 25%

time in min


Pectin


0

1

2

3

4

5

6

7

0 20 40 60 80 100 120 140

time

wat

er u

ptak

e in

%

cellulose microgranular cellulose fibrous medium cellulose fibrous long

time in min


Conclusions

For CRM user:• be aware of hygroscopicity of CRMs (i.e. avoid long exposure to environmental humidity)• perform water content determination accurately (chose the rightmethod)For CRM producer:• check the homogeneity (e.g. online NIR-spectrometer)• water content is a source of uncertainty (in some cases the

major source)

• Water uptake kinetics and water uptake capacity depend on the composition of the sample

• High temperatures (oven method) may cause decomposition of the material → higher moisture contents

Influence of Water on the Property Values of Certified ... · Workshop on water in food - 30th of...

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