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Inside this Issue

August 2008 – Issue 35

Agilent ICP-MS Journal

2-3 Comparison of Cell Modes for the Measurement of InterferedAnalytes in a Complex Matrix

4-5 User Article: Food Regulatory Lab Moves to HMI/7500cx ICP-MS

5 Design Changes on GC Interface for 7500 Series, Much Faster Gas Switching Times with H2 Vent Valve, Quick Start Guide to Agilent 7500 Series ICP-MS ChemStation

6 New MassHunter Software Platform for the 7500 Series

7 Take the Mass-ter Mind Challenge, FREE ICP-MS Vials with ICP-MS Supplies, New Elemental Bio-Imaging Facility, All Aboard for the French User Group Meeting

8 TDK’s Global Environmental Award, Trade Shows and Conferences, New Agilent ICP-MS Users, 4500 Series Reaches EOS, New ICP-MS Publications

2 Agilent ICP-MS Journal August 2008 - Issue 35 www.agilent.com/chem/icpms

Comparison of CellModes for theMeasurement ofInterfered Analytesin a Complex Matrix Ed McCurdy, Glenn WoodsAgilent Technologies UK Ltd

IntroductionMuch of the published work relatingto collision/reaction cell (CRC) technology has focused on single-element reaction process methods,most of which are of little relevanceto more routine laboratories, whichuse ICP-MS as a commercial tool formulti-element analysis in complexand variable matrices. The 3 mostimportant potential limitations ofany cell method are rarely addressedin the published work, namely:

1. Failure to remove unreactive interferences

2. Creation of new, cell-formed reaction product ions, and

3. Loss of analyte sensitivity by reaction.

The comparative tests were designedto investigate the true effect of thesepotential issues, and to answer thequestion of which mode, collision orreaction, is more effective for multi-element analysis in a complex sample matrix. The complex matricescomprised 5% HNO3, 5% HCl, 1%H2SO4, 1% Acetic Acid, 200ppm Na,200ppm Ca and 500ppm P. Each ofthese matrix components was prepared individually as a singlematrix solution, and a final, combinedmixed matrix solution sample wasprepared, containing all of the individual matrix components.

Analytes & Matrix ComponentsA full list of the elements measuredand the isotopes used is given onpage 35 of the Agilent ICP-MSPrimer [1] along with a list of the potential polyatomic interferenceswhich might arise in the complexmatrix in which the analytes were tobe measured. At least 1 polyatomicinterference could occur on everyisotope of every element in the massrange 45 to 80, also the variouspolyatomics which overlap each analytemass typically arise from differentmatrix components.

calculated against the calibration in0.1% HNO3, and the resulting concentrations in each cell gas modewere plotted against the matrixname. This gave a series of comparisonplots, showing the background equivalent concentration (BEC)plotted against the matrix, for eachanalyte in each gas mode. Since allthe samples in these plots wereunspiked matrices, all the resultsshould be zero, so any positive resultindicates an incompletely removedor newly-created interference.

Figure 1 shows the BEC for As (measured at mass 75) in each gasmode, plotted against each matrix.

The He mode data were consistentand at a low level, as would beexpected since all these samples

Tuning and Data AcquisitionThe 7500cx was tuned in each of the3 modes (No-Gas, He and H2), usingthe standard Agilent-recommendedrobust tuning conditions. The samplesequence was prepared, with a 2-pointmulti-element external calibration,stabilized with 0.1% HNO3 (the zeromatrix calibration reference). All theremaining sample matrices were thenmeasured against this external calibration. No internal standards wereadded. Each sample was measured inall 3 gas modes, from a single visit toeach vial. The standard Agilentmulti-step rinse program was used,in conjunction with pre-emptive rinse.

Results and DiscussionThe measured or apparent concentration of each analyte was

Figure 2. Comparison Plot of Sc45 BEC vs Sample Matrix for All 3 Cell Gas Modes

Figure 1. Comparison Plots of As75 BEC vs Sample Matrix for All 3 Cell Gas Modes

were unspiked matrices. However, theNo-Gas mode data showed a markedpositive bias for As in the 5% HClmatrix, due to the interference fromArCl, which contributes to the signalat mass 75. This interference wasremoved effectively in reaction mode(H2 cell gas), since ArCl is highlyreactive with H2 cell gas.

In the mixed matrix (the final pointon the x-axis), the apparent As concentration in No-Gas mode wasmuch higher than in the HCl matrixalone (about 38ppb, compared toabout 5ppb). This is because themixed matrix contained the Ca derived from the 200ppm Ca matrix,as well as the Cl from the 5% HClmatrix, leading to the formation of anew CaCl polyatomic interferenceon As, which was not seen in any ofthe single-component matrices.

It is interesting to note that, whileH2 mode was effective in removingArCl, it did not completely remove theCaCl interference on As, illustratingthe point that not all of the interferences at any given analytemass may react with the same reactiongas. He mode, since it works by collision processes and is thereforeeffective against ALL polyatomicions, gave a consistent low backgroundfor As, even in the mixed matrix.

For some combinations of analyteand matrix, another important problem of reactive cell gases wasobserved, as illustrated in Figure 2,for Sc45 in the Ca matrix.

Once again, the apparent Sc concentration measured in He modewas low and consistent in all the different single matrices, and in themixed matrix. In the No-Gas cellmode a polyatomic interference wasobserved on Sc in the 1% acetic acidmatrix, due to the formation of theCO2 polyatomic ion in this matrix.This polyatomic was reduced but notcompletely removed in H2 mode. Inthe Ca matrix, however, the level ofpolyatomic interference on Sc wasrelatively low in No-Gas mode (andessentially zero in He mode), but muchhigher in H2 mode. This is becauseH2, being a reactive cell gas, reactswith Ca to form a new cell-formedreaction product ion, 44CaH, greatlyincreasing the interference on Sc45.

The third potential issue with theuse of a reactive cell gas is the loss ofanalyte sensitivity as a result of theanalyte ions reacting with the cell gas. A comparison of the spectra for

analytes relative to Co, which was itself significantly reduced in H2mode, in real terms, the relative lossof sensitivity for Ni and Cu wasactually much greater than is apparent from these plots, by a factorof 20x, relative to Zn. This loss ofanalyte sensitivity by reaction is oneof the main reasons why reactive cellgases are not widely used successfullyfor multi-element applications.

ConclusionsFor multi-element analysis in a complex, multi-component matrix, itis clear that He collision mode is moreeffective and produces more reliabledata than H2 reaction mode. Reactionmode has 3 key drawbacks: inabilityto remove unreactive interferences,creation of new polyatomic species,and significant loss of sensitivity forcertain analytes due to reaction.

Reference1. ICP-MS Primer, page 34, AgilentTechnologies publication 5989-3526EN

the 10ppb calibration standard (i.e. inthe absence of any matrix components)is shown in Figure 3. In No-Gas mode(top), the measured peak patternshowed Co59 having the highestintensity, followed by Ni58 andCu63, with Zn64 and the minor isotopes all being lower.

In He collision mode, this generalpattern of peak intensities wasmaintained, although the spectrumdemonstrated a slight increase inmass bias, due to scattering of thelighter ions.

In H2 mode, by contrast, the highestpeak was Zn64, followed by Co, andthen the minor Zn isotopes at mass 66and 68. The relative intensities ofthe Ni and Cu peaks (and to a lesserextent the Co59) were dramaticallyreduced, compared to the relativesensitivity in No-Gas mode. The peakintensities are shown relative to Co59, to remove any differences inabsolute sensitivity between cell gasand no cell gas modes. It is clearthat, since the comparison was based on the sensitivity of the other

3www.agilent.com/chem/icpms Agilent ICP-MS Journal August 2008 - Issue 35

Figure 3. Relative Sensitivity forAnalytes Co, Ni, Cu and Zn, in No-Gas Mode (top), He collisionmode (middle) and H2 reactionmode (bottom)

Candy A Candy A Candy A Candy A

Dilution 10 10 1 1

75As 0.68 0.49 0.50 0.57

208Pb 0.74 0.72 0.70 0.70

Candy B Candy B Candy B Candy B

Dilution 10 10 1 1

75As 1.23 1.26 1.25 1.25

208Pb 1.99 1.94 1.96 1.95


Food Regulatory LabMoves to HMI/7500cxICP-MS Robert Sheridan, Thomas KingDivision of Food Laboratory at New York StateDepartment of Agriculture and Markets, USAwww.agmkt.state.ny.us

IntroductionA team from the Division of FoodLaboratory at New York StateDepartment of Agriculture andMarkets, USA recently evaluatedICP-MS in a move to strengthen itstrace metal analytical capability. Thedepartment supports consumer protection by testing foods for purity,quality and accurate labeling in NewYork State. The chemistry section ofthe food lab is responsible for tracemetals analyses from pesticide residuesto heavy metals in foods and animalfeed. Example applications include:• Pb and As levels in fruit juices • Pb in candy • Pb in maple syrup • Pb, As, Cd, Cr and Se in various

other foods.To date the lab has relied on ICP-OES for these analyses but achievingdesired limits of detection (LOD) canbe difficult because of the inherentlack of sensitivity of ICP-OES.Current method LOD’s are veryclose to the regulatory limits andcertain matrix interferences cancause further problems with ICP-OES.

ICP-MS is well known for its highsensitivity compared to ICP-OES.Matrix interference management byICP-MS is also well establishedthrough the use of collision/reactioncell (CRC) technology. A final barrierto overcome, and of particular relevance to food testing, has beenthe matrix tolerance of ICP-MS compared to ICP-OES. Traditionallysamples prepared for analysis byICP-MS have needed to contain lessthan 0.1% total dissolved solids (TDS).However, the recent development ofthe High Matrix Introduction (HMI)system for the Agilent 7500cx allowssamples containing higher levels ofTDS, up to 1%, to be analyzed by ICP-MS.

Evaluation of ICP-MSICP-MS instruments from Agilentplus two other manufacturers wereevaluated. The main criteria were:• Exceed regulatory limits for Pb,

As, Cd, Cr and Se in various food matrices

Table 3. Repeat results for As and Pb in pear juice(ppb), using different dilution factors

Figure 1. As calibration curve

The pear juice was analyzed at 50and 10:1 dilutions. Again the diluentwas 1% HNO3/0.5% HCl.The Pb results (Table 3) were identicalfor both dilutions and the arsenicresults were within 10%. This meansthat pear juice can be analyzed at10:1 dilution with the HMI/7500cx.Avoiding a larger dilution, whichmay result in error and poorer levelsof detection, is a key advantage ofthe method.

Advantages of HMI/7500cxNew York State Department’s FoodLab decided in favor of the AgilentHMI/7500cx ICP-MS system because

• Capability to analyze additional elements at low levels

• Improve sample throughput• Ability to handle high matrix

samples.

Agilent 7500cx with HMIBert Woods, the ApplicationsSpecialist who demonstrated theAgilent 7500cx didn’t request detailedinformation about the sample prepstage of the food samples or theirTDS content. He was confident thatsamples prepared for analysis byICP-OES could be analyzed by theHMI/7500cx in helium mode with noor limited dilution.

ExperimentalAs and Pb were determined in twodifferent candy digests (sample Aand B) and a pear juice sample bythe HMI/7500cx in He mode – seeTable 1 for operating conditions.

Table 1. HMI/7500cx ICP-MS operating conditions

ResultsThe candy digests were analyzeddirectly and 10:1 diluted in 1%HNO3/0.5% HCl. The results (Table2), which were the same for theundiluted and the 10:1 diluted samples, show that the sample canbe analyzed directly, with good sensitivity. The calibration curve forAs (Figure 1) confirms that the40Ar35Cl interference on 75As hasbeen removed by adding helium gas tothe Octopole Reaction System (ORS).

Parameter Setting

RF power 1600W

Sample depth 10 mm

Carrier gas 0.3 mL/min

Make up gas 0.82 mL/min

He gas flow 4 mL/min

HMI setting Robust (software setting)

Table 2. Repeat results for As and Pb in two candy digests (ppb), using different dilution factors

Pear Pear Pear Pear

Dilution: 50 50 10 10

75As 63.3 61.2 67.2 67.6

208Pb 4.87 4.56 4.48 4.42

of its ability to analyze high matrixfood samples and digests preparedfor ICP-OES analysis, with ICP-MSlevels of detection following minimalor no dilution.

The sample throughput capability ofICP-MS was also evaluated.Operating the 7500cx in a single analysis mode (helium mode) reduced the analysis time per sampleto less than one minute.

Future ProofingInvesting in ICP-MS also insures thatthe lab is well placed to meet anyfuture regulations pertaining tofoods that the US Food and DrugAdministration (FDA) may introduce.Currently the FDA has a limit of 0.1ppm for Pb in candy and 10 ppb Asin drinking water.As the capability for detecting moreanalytes improves, regulators mayconsider rules for products previouslynot considered, such as As and Pb infruit juice.

Design Changes onGC Interface for the7500 Series Tomo YamadaICP-MS Product Manager, Tokyo AnalyticalDivision, Agilent Technologies

A modified Agilent GC Interface –used to couple Agilent’s GC to the7500 Series, is available from August2008. The design has been changedfor easier installation and better performance. The new product numberis G3158B.

Figure 1. New alignment tool

Enhancements:• The injector alignment tool (Figure 1)

has been modified for easier alignment. The new design allows

Quick Start Guide toAgilent 7500 SeriesICP-MS ChemStation Paul McMahonICP-MS Technical Marketing Engineer, TokyoAnalytical Division, Agilent Technologies

The ICP-MS ChemStation QuickStart Guide is a brief (40 page) colormanual that describes how to usethe Agilent 7500 Series ICP-MSChemStation from instrument startupthrough to sample analysis and datahandling. The guide is useful to allICP-MS ChemStation users, butanyone doing environmental analysiswill find it especially useful.

Topics discussed include:Startup, Getting Started, Things tocheck before analysis, Preparetuning solutions, Ignite the plasma,Check tuning, Quantitative methodsetup, Set up the Sequence, Analyzethe samples, Analyze the data(Quantitative Analysis), OtherFeatures, Quality Control (IntelligentSequencing), Semi-quantitative Analysis,Batch View.

Download a copy of the guide fromthe Agilent ICP-MS User Forum.

To access the Forum, you will needto log-in to the Agilent web site, orregister, if you haven't done so previously. You will be asked toenter your instrument's serial numberon your first visit only. Look for thelink to the ICP-MS User Forum from:www.agilent.com/chem/icpms

the injector center position to be located more easily. The Z-positioncan also be set with the tool.

• The torch connecting clamp screws have been modified for easier assembly.

• The Ar preheat tubing coil is now located in the GC valve box. This insures that the temperature of the makeup Ar is kept stable during GC oven temperature changes.

• The modified interface now supports the Agilent 7890 GC in addition to the 6890 GC. New 7890 GC firmware (revision A.01.09) has a preconfigured heatzone setup specifically for the modified GC-ICP-MS interface.

Tip and Trick:Much Faster GasSwitching Timeswith H2 Vent Valve Tomo YamadaICP-MS Product Manager, Tokyo AnalyticalDivision, Agilent Technologies

7500cs (G3273B version) mainframes,and 7500cx mainframes (G3272Bversion) fitted with the optional H2cell gas line, are now equipped witha new cell gas evacuation assistvalve. The valve allows much moreefficient venting of H2, and so reducesthe stabilization time needed whenswitching from H2 to another gasmode.

With the vacuum assist valve, therecommended order in which gasmodes are used is now:No-Gas � He � H2.

Using this new sequence will shortentotal analysis time, since H2 modestabilizes and vents quickly (typically10-15 sec), and No-Gas mode stabilizesduring rinse and sample uptake.

Check your mainframe model numberto confirm you have the evacuationassist valve fitted: all G3273B andG3272B (with H2 line) mainframesincorporate the valve.



NEW!MassHunter SoftwarePlatform for the 7500Series Tomo YamadaICP-MS Product Manager, Tokyo AnalyticalDivision, Agilent Technologies

IntroductionAgilent has developed an all-newsoftware platform which will replacethe ChemStation software: theMassHunter Workstation software isbased on the highly successfulMassHunter LC/MS software andwill become common to all AgilentMS products.

There are many new features, butkey features of MassHunterWorkstation (A.01.01) are:• Batch-at-a-glance data review

(Figure 1)• Outlier flagging (Figure 2)• Reporting via Excel 2007

Batch-at-a-glance Data ReviewFrom this new data analysis window,all necessary information can beeasily reviewed – e.g. analyticalresults, spectra, calibration plots,ISTD stability chart, allowing theuser to: • Review samples more easily• Review sample data in real time• Customize the window layout.

Outliers - Automatic flagging Outlier values, such as count RSD,ISTD recovery, calibration linearity, calibration range, etc. are automatically flagged and displayedin the batch table. • Color coding allows the user to

identify and review the outliers.• Potential analytical problems can

be located immediately.• Filters can display only samples

that have outliers.

Reporting via Excel 2007 • MassHunter Workstation ships

with Microsoft Excel 2007. • Export menu directly generates an

Excel file - saving time.• Analytical results or calibration

information including BEC and DL are exported to Excel.

• The reporting templates are Excelfiles.

MassHunter Workstation family –currently used on Agilent TOF, Q-TOF and triple quadrupole LC/MSsystems. LC/MS users will find thesame familiar interface now on ICP-MS.

AvailabilityThe 7500 Series will be availablewith either ChemStation orMassHunter (with new ICP-MSorders only) during the transitionperiod. Contact your ICP-MS specialistto find out which one is recommended.An upgrade for existing 7500 userswill be available at the end of theyear.

Other New Features:• Standard Addition calibration plot

is automatically converted to an external calibration plot – no userintervention required.

• SemiQuant factors are automaticallycorrected in the sequence – no need for manual update.

• Spectrum overlay.• Plus many other improvements.

Figure 2. Outlier flagging

Agilent MassHunter WorkstationThe MassHunter Workstation for the7500 Series is part of the Agilent

Figure 1. Two examples of batch-at-a-glance data review

Take Agilent’s Mass-ter-Mind ChallengeRich QuashneMarketing Program Manager, AgilentTechnologies, Little Falls, USA

Put your ICP-MS knowledge to thetest against other experts from aroundthe world. Answer the most questionscorrect in the shortest time to winFREE Agilent products.

Every player will receive a specialoffer for ICP-MS supplies.

Register and play at:www.mass-ter-mind.com

Receive FREE ICP-MSVials with ICP-MSSupplies Purchase over $1200 (USD) of AgilentICP-MS supplies and receive a FREEpack of ICP-MS vials for the AgilentIntegrated Autosampler (I-AS).

Your choice of either:

• 6ml vials for Tray A-89 position, 200/pk (Part #G3160-65303)

• 18ml vials for Tray B-53 position, 55/pk (Part #G3160-65304)

Better Results with Genuine Parts With Agilent ICP-MS supplies andaccessories, the difference is in thedetails. All our products have beenengineered or selected by our instrument design teams, manufactured to our demandingspecifications, and tested under avariety of conditions. You can besure that you’re getting the best possible results for your analysis byusing genuine Agilent ICP-MS components.

All Aboard for theFrench User GroupMeeting Jérôme DarrouzèsICP-MS Specialist, Agilent Technologies,France

On 13th April 2008, twenty five 7500and 4500 users boarded the “LaBretagne” barge, moored close to theEiffel Tower, for the 3rd annualFrench Agilent ICP-MS user meeting.

ICP-MS Specialists, Jérôme Darrouzèsand Laurent Naëls, updated users onthe latest technological, applicationand support developments fromAgilent and were on hand to providefeedback during the various Q and Asessions.

Special thanks go to FrédéricCandaudap (LMTG, Toulouse) andStéphane Dubascoux (LCABIE, Pau) fortheir respective excellent contributionson the capability of He mode in geological matrices and the couplingof FFF (field flow fractionation) toICP-MS for the study of colloidalfractions.

Lunch provided the opportunity forinformal chat while cruising on theSeine and taking in the sights ofParis.

Look out for details of the nextFrench ICP-MS User Meeting alreadyplanned for early 2009.

Details of the Worldwide User Groupmeeting to be held at the WinterPlasma Conference in Graz in Feb2009 will be available on-line soonfrom www.agilent.com/chem/icpms

New Elemental Bio-Imaging Facility Tony CrockerAgilent Technologies, Australia

Agilent’s Rudy Grimm (center) and ToshiakiMatsuda (right) celebrate with UTS on the opening of the Elemental Bio-Imaging Facility inJune 2008.

Considered a world first, theElemental Bio-Imaging Facility basedat the University of Technology,Sydney (UTS), Australia, will beinvolved in metallomics researchthat examines the study of metalsand their interactions with proteinsin the body.

With increasing evidence that theexcessive accumulation or imbalanceof metals play a role in the developmentof neurodegenerative disorders suchas Alzheimer’s and Parkinson’sdiseases, scientists at UTS arepioneering the use of laser ablationICP-MS in their research. The technique involves ablating thin sections of human/animal tissuesuch as the brain and employingtwo-dimensional imaging to map thelevels and distribution of variouselements. When combined withother diagnostic technologies, LA-ICP-MS results may lead to a breakthrough in understanding theseconditions.

The centre has recently purchasedtheir second Agilent 7500 ICP-MS,linked to a New Wave Research laser.


This information is subject to change without notice.

© Agilent Technologies, Inc. 2008Printed in the U.S.A. August 19, 20085989-9240EN

Karen Morton for Agilent Technologiese-mail: [email protected] ICP-MS Journal Editor

TDK Win GlobalEnvironmental AwardOn February 20th 2008, TDKCorporation was awarded the highest honor at the Fuji SankeiGroup’s 17th Global EnvironmentalAward Grand Prize ceremony for theirpioneering work on trace metal contamination of electronic compo-nents.

TDK have significantly reduced theamount of acid and heat they use intheir sample prep procedures bydirectly analyzing constituent partsand solid materials with theirAgilent laser ablation-ICP-MS system.Compared to the old methodology,the LA-ICP-MS approach requires90% less reagents and has cut CO2emissions by about 60%.

The judges were also impressed byTDK’s openness to share their technological advances across theTDK group and industry throughtheir participation at conferencesand seminars.

Trade Shows andConferencesJAIMA ShowSeptember 3-5, 2008Chiba, Japan

Isotrace 2008September 9-11, 2008Lyon, France

German ICP-MS All User ConferenceSeptember 17-19, 2008Dresden, Germany

Winter Conference on Plasma Spectrochemistry Feb 15-20, 2009Graz, Austriawww.winterplasmagraz.at

New Agilent ICP-MS UsersA very warm welcome to all companies and institutions that have recently addedan Agilent ICP-MS to their analytical facilities. Remember to join the Agilentweb-based ICP-MS User Forum – the place where you can exchange informa-tion relating to your new ICP-MS. You will also find a host of resources in theForum designed to help you get the most from your 7500.

To access the Forum, you will simply need to log-in to the Agilent web site, orregister if you haven't done so previously, and enter your instrument's serialnumber on your first visit only. Look for the link to the ICP-MS User Forumfrom: www.agilent.com/chem/icpms

4500 Series Reaches EOS The Agilent 4500 Series ICP-MS has reached its End of Support (EOS). For more information on transitioning to the 7500 Series, contact your Agilentsupport sales representative or visit: www.agilent.com/chem/icpms

Agilent ICP-MS PublicationsTo view and download these latest publications, go towww.agilent.com/chem/icpms and look under "Library Information"

Agilent has developed a new,informative poster specificallyfor your lab wall. By outliningthe basic principles of ICP-MSin an easy to follow and clearway, the poster will help youwhen you need to explain thetechnique to your colleaguesor visitors.

• Title: “Fundamental Principles of the Agilent 7500 Series ICP-MS with Octopole Reaction System”, 5989-8628EN.

• Dimensions: 36” x 28” (96 x 71cm).

• Order a copy of the poster on-line or from your local Agilent office.

Mass Card: Periodic Table/Relative Isotopic Abundance Table, 5989-8540EN

Technical Feature: Heavy Metals Content of Dietary Supplements by Agilent7500 ORS ICP-MS, 5989-8813EN

Front page photo:Peter Planitz, long serving Agilent ICP-MS Application Engineer based inGermany.

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