PetruJitaru

French Agency for Food, Environmental and Occupational Health & Safety (ANSES) Head of unit “Trace Metals and Minerals” / Department of food chemical contaminants Laboratory for food safety / Department of food chemical contaminants 14, Pierre & Marie Curie, F-94701 Maisons-Alfort, France Phone (office) : +33. 1. 49.77.28.43; E-mail : petru.jitaru@anses.fr; Website : www.anses.fr

Curent status and future perspectives in terms of

trace elemental speciation analysis in food products

== TEAM ==

Rachida Chekri Axelle Leufroy Nathalie Marchond Claude Chafey Julie Zinck Cristian Testu Alin Dirtu (post-doc) Lucas Givelet (PhD student) Marina Saraiva (PhD student) Micheline Ghosn (PhD student) Marian Ribeiro Mendes (PhD student) Clémence Laurent (technician) Hanae Belmir (Master student) Thierry Guérin - head of department

PARTI.BRIEFOVERVIEWREGARDINGOFICIALANALYSESOFFOODPRODUCTS

PARTII.SPECIATIONANALYSISAPPLIEDTOFOODSTUFF

PARTI.

BRIEFOVERVIEWREGARDINGOFICIALANALYSESOFFOODPRODUCTS

1)Qualitycontrol(rawmaterialsandfoodproducts)

(2)NutriMon(biomedical…)

(3)AuthenMcity/fraudassessement

(4)Control/surveillanceplans⇒oficialanalysesatEUornaMonallevel

…

DIFFERENTSTYPESOFCHEMICALFOODANALYSIS

Europeanreferencelaboratory(EURL)

CoordinaMonoftheNaMonalReference

Laboratories(NRL)

CoordinaMonofthelocal

(rouMne)laboratoriesNetworkofrou,neFrenchlaboratoriesfor

tracemetalsinfoodofanimalorigin

FordeclaraMonsofconformity,theexpandeduncertainty(k=2)issubtracted

fromtheresult.

Acloserlookatofficialanalysesoffoodproducts

A lot/sublot is refused if the analyMcal result of the laboratory sample

undoubtedly exceeds the applicablemaximum level set by the European

RegulaMon, taking into account the wider measurement uncertainty (EC

RegulaMonN°333/2007).

Officialanalysisofafoodproducts⇒declaraMonofconformityisissued.

Reportedresultofanofficialanalysis⇒ " −$

Uisover-esMmated⇒trueresult⇒healthriskforthepopulaMon

Uisunder-esMmated⇒trueresult⇒economicimpact(destrucMonoflotsoffoodproducts,etc.

TheCompliance/non-complianceofan“official”resultmaybebiasedbyaproblemrelatedto:

1)Accuracy

2)Uncertainty(especiallyinthecaseofresultsclosetothemaximumadmissiblelevel/regulatedvalue)

PropervalidaMonofanofficialmethod(includingtheassessmentofuncertainty)isfundamentaltoobtainreliablemeasurementsof

chemicalcontaminantsinfoodproducts.

IUPACTechnicalReport:«HarmonizedguidelinesforsinglelaboratoryvalidaAonofmethodsofanalysis»,PureAppl.Chem.,2002,74(5),835-855.Methodvalida,onmakesuseofasetofteststhatbothtestanyassump,onsonwhichtheanaly,calmethodisbasedandestablishanddocumenttheperformancecharacteris,csofamethod,therebydemonstra,ngwhetherthemethodisfitforapar,cularanaly,calpurpose.

MethodvalidaMon…

ISO/IEC17025:2005cl.5.4.5.1(Valida,onofmethods)Valida,onistheconfirma,onbyexamina,onandtheprovisionofobjec,veevidencethatthepar,cularrequirementsforaspecificintendedusearefulfilled.

METHODVALIDATIONIMPLIESACOMPARISONOFTHEANALYTICALPERFORMANCESWITHTHECUSTOMER’SREQUIREMENTS!

Mainparameterstobevalidatedfortheassessmentofmethod’sfitness-for-purpose:

(1)  Trueness:accuracy+precision

(2) Uncertainty

(3) Detec,on&quan,fica,onlimits(LOD,LOQ)

(4)  Selec,vity

(5)  Ruggedness…

(1)LOQandLOD

Matrix

LOQ(mg/kg)

Asi

Pb Cd Hg

Fish/seafruits - ≤0.06 ≤0.02 ≤0.1-0.2

Meat - ≤0.02-0.1 ≤0.02-0.2 -

Milk - ≤0.013 - -

Honey - ≤0.02 - -

Rice ≤0.02-0.06 - - -

EU(“customer”)requirementsformethodstobeusedforoficialanalysesintermsoftracemetalsinfood

Parameter

(mg/kg)

Pb As-Cd-Hg

ML ≤0,01 >0.01and≤0.02 >0.02and<0.1 ≥0.1 <0.10 ≥0.10

LOQ ≤ML ≤2/3×ML ≤2/5×ML ≤1/5×ML ≤2/5×ML ≤1/5×ML

LOD ≤ML ≤2/10×ML ≤3/25×ML ≤3/50×ML ≤3/25×ML ≤3/50×ML

(2)Uncertainty

Anofficialmethodforfoodcontrolmustprovideacombineduncertainty<umax

c(mg⋅kg-1) α ≤0.05 0.20

0.051-0.5 0.18 0.501-1.0 0.15 1.001-10 0.12 >10 0.10

( )22

max 2u cLOD

α+⎟⎠

⎞⎜⎝

⎛=

Maximumamissiblelevel(mg/kg)

Fishery

products

Meat Milk

Honey

Pb 0.3 0.1-0.5 0.02 0.1

Cd 0.05-1.0 0.05-1.0 -

Hg 0.5-1.0

Matrix

umax

(mg/kg)

Pb Cd Hg

Fish/seafruits 0.056 0.011-0.16 0.093-0.16

Meat 0.019-0.056 0.011-0.16 -

Milk 0.0037 - -

Honey 0.019

umax

=10-20%(dependingonthetargetconcentraMon)

umethod,maximum

<20%(dependingonthetargetconcentraMon)

Umethod,maximum

<40%(dependingonthetargetconcentraMon/ML)

Accuracyprofile⇒graphicalrepresentaMonoftheaccuracygenerallyexpressedintermsof

recoveryfactoroverarangeofanalytelevelscomprisedbetweentheLOQandanin-house

definedconcentraMonimposingtwolimits:

METHODVALIDATIONBYMEANSOFTHEACCURACYPROFILE:

AREALISTICAPPROACHFOROFFICIALCHEMICALLABORATORIES

TITITI Skβ ×=2β1ν,TI tk += ⎟

⎠

⎞⎜⎝

⎛ += 2RTI IJB11SS

SR,standarddeviaMoncharacterizingthewithin-laboratoryreproducibility;

I,numberofseries(days);

J,numberofmeasurementreplicatesperseries;

B,parameterdependingonintra-andinter-seriesstandarddeviaMons

Sr,S

B,intra-andinter-seriesstandarddeviaMon,respecMvely

1JA1AB

++

= 2r

2B

ssA =

o  acceptability interval (λ): the maximum accepted devia,on of a measurement result compared to a reference value(generallyλ≤30%).

o  toleranceinterval(β-expecta,oninterval):definesanintervalinwhichagivenfracMonoftheresults(β,%)willbefound.

Recoveryfa

ctor(%

)

Concentration100

C1 C2

C3 C4C5

120

80

110

90

AveragerecoveryfactorfortheanalysisofaCRMoraspikedmatrix

Higheracceptancelimit(100+λ,%)

Loweracceptancelimit(100-λ,%)

Highertolerancelimit(+β,%)

Lowertolerancelimit(-β,%)

LOQ

AnalysisofCRMorspikedsamplesgenerallyatfiveconcentraMonlevels(atleast)iscarriedoutinduplicateindifferentdaysduring

aMmespanofatleastthreemonths.

PartII.

SPECIATIONANALYSISAPPLIEDTOFOODSTUFF

IUPAC(D.M.Templetonet.al.,PureAppl.Chem.,2000):speciaMonanalysis⇒

theanalyMcalacMvityofidenMfyingand/ormeasuringthequanMMesofoneormoreindividual

chemicalspeciesinasample.

«Inorganicarsenic»isafracMonofarsenic(AsIII+AsV)andnotaspecies!

q  MercurypoisoningatMinamata,Japan(1950’):thefirstlargescalepoisoningwith mercury species(CH3Hg+)viafishconsump,on(CH3Hg+was

generatedintheprocessforproducingacetaldehydeusingmercuryascatalystinalocalfactory)

q  2250peopleneurologicallyaffected,1040died

“Minamatadisease”

enteredintoforceon

16August2017.

(109countriessofar) hep://www.mercuryconven,on.org/

AbriefhystoryofspeciaMonanalysis…

q  Minamatadisease»isoneofthemostsignificantnegaMveconsequencesassociatedwithenvironmental

polluMoncausedbyindustrialacMvityintheworld

q  Thefisheryproductscontained5to40ppmofHg⇒maximumadmissiblelevelisnowadaysof1.0ppmfor

thepredatoryspecies

70yearslater…

q  Despite the advanced analyMcal methodologies nowadays

available,thereisnotasingleEUregulaMonintermsofspeciaMon

analysis in food products⇒ excepMon: Sn(IV) in canned foods

(since 2006) ⇒ related to contaminaMon via food contact

materials.

Sn(IV)

q  NoregulaMonyetforMeHg(atleastinfish)despiteitstoxicity.

q  RegulaMonexistsforinorganicarsenic(AsIII+AsV)⇒fracMonnotspecies!

(Inorganic)Arsenic ML(mg/kg)

Milledrice,notparboiled(polishedriceorwhiterice) 0,2

Parboiledriceandhuskedrice 0,25

Aglewesofpuffedrice,derizleaves,ricecrackersandrice

flourcakes

0,30

RicefortheproducMonoffoodstuffsforinfantsand

youngchildren

0,10

Dailyexposure:

Ii:dailyintake(µg/day)

Di:dailyconsumpMonoftheconcernedfood(g/day)

Ci:averageconcentraMonoftheelement(µgg-1)

DailynutriMonalintake

Ei:dailyexposure(µg/kgbw/day);BW:bodyweight(kg)

Ii=D

i×C

i

"#=%↓# /&' 

WhythereisalackinregulaMonintermsofspeciaMonanalysiswhenreferenceanalyMcalmethodologiesareavailable?

the basis of regulaMon of chemical contaminants in foodstuffs is a compromise between the risk assessment and the

economicalimpact.

ExemplesofPTDI(μg/kgbw/day)

MeHg:0.19(JECFA+EFSA)

Hg(II):0.57(JECFA)

Inbrief,riskassessmentimpliesthecomparisonofthedaily(weeklyoryearly)exposurewiththeprovisionaltolerabledaily(weeklyorweeklyoryearly)intake(µg/kgbw/day)(toxicologicalreferencevalue).

TotalDietStudies(TDS):themostcomprehensivetoolforriskassessmentofthegeneral

populaMon

Mainchemicalspeciesofinterestintermsoffoodanalysis

Increasingmolecularmassandcomplexity

INORGANICCOMPOUNDSAND

COMPLEXESNispecies:Ni0,NiO,NiCl2,NiSO4,NiCO3Ti species:Ti,TiCl4,TiO2Nanoparticles

ELECTRONICANDREDOXSTATESSe(IV)/Se(VI)As(III)/As(V)Cr(III)/Cr(VI)Fe(II)/Fe(III),…

STABLEISOTOPES

ORGANOMETALLICCOMPOUNDS

MACROMOLECULARCOMPOUNDSANDCOMPLEXES

ORGANICCOMPLEXES

MLn

Toresume:

q  As(III)-As(V)(todefinetheinorganicfracMon…)

q  Cr(III)-Cr(VI)(notregulated)

q  MeHg(notregulated)

q  OrganoMn(notregulated)

q  Organicmoleculescontainingheteroatoms(Cl,Br,S,metals)(parMallyregulated)

MainAscontributorsviafood

(1)Riceandcereals

I.SpeciaMondefinedfromthepointofviewoftheoxidaMonstate

I.1.Inorganicarsenic:As(III)andAs(V)

arsenite: As(III)arsenate: As(V)

(cancerigen)

Acide monomethylarsonic (MMA); Acide dimethylarsonic (DMA)

(Cancer promoter?)

Organic As : arsenobetaine (AsB)arsenocholine (AsC)

trimethylarsineoxyde (TMAO), arsenosucres, arsenolipides, etc.

(non-toxic)

q  maincontributora}erdrinkingwater

q  mainlycontaminatedwithinorganicAs

q  Despite the relaMvely large panel of As species present in food, rice accumulatesmostly arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA),

dimethylarsinicacid(DMA),

q  ArseniclevelsinricedependonthegeographicallocaMon,growing/soilcondiMonsandalsoonthelevelofcontaminaMonoftheirrigaMonwater.

Ast⇒0.041-0.54mg/kg

Asi⇒0.025-0.47mg/kg(organicriceduo)

q  37compositesamples

q  7groupsofricetypesmostlyconsumedinFrance:BasmaM,Thai,White,White

forrisowo,Organicsemi-wholegrainduo,Three-ricemixandWholegrainrice

q  Theintakevariedbetween0.18µgkg-1b.wforAstand0.002and0.15µgkg-1

b.wforAsi⇒wellbelowthatprovidingaminimalriskofchronictoxicity.

q  Organic wholegrain ricemay entail a significant risk for children in case of

soleconsumpMonattheexpensesofpolishedrice.

OverviewofarseniclevelsinricesampledinFrance

(2)FishasAscontributor

Level(mg/kg) %Asi

(min-max)

%AsB

(min-max)Mean min-max

Asi

0.022 0.004-0.096 0.72%

(0.13-2.7)

81%

(58-96)AsB 2.5 0.006-15.1

Astotal

3.07 0.013-12.9

OverviewofAsspecieslevelsinfish

q  PS/PCfish2011/2012:85fishsamples

q  25differentfishspeciescollectedfrom22Frenchregions

q  primarilyorganicAsspecies(non-toxic)

q  noregulaMon

Level(mg/kg) %Asi

(min-max)

%AsB

(min-

max)Mean min-max

Asi

0.16 0.006-1.30 6%

(0.33-10.0)

51%

(41-84)AsB 1.34 0.12-3.94

Astota

2.64 1.30-6.54

(3)BivalvemolluscsasAscontributor

OverviewofAsspecieslevelsinbivalvemolluscs

q  PS / PC bivalve molluscs 2017: 54 samples (mussels

andoysters)

q  27 samples of oysters and 27 samples of mussels

collectedfrom6frenchregions

Asimolluscs

>Asifish(8foldinaverage)

MILK,apotenMalcontributorofAsi?

Surveillanceplan(2016)concerningthetotalandinorganicAsinbovine

milk

ConcentraMon(mg/kg)

TotalAs 0.00040(LOD)–0.0019

InorganicAs 0.00010(LOD)-0.00030

Asi/As

t≤16%

50samplesdistributedacrossthewholecountry

Specia,onanalysisofAsatultra-tracelevels

1)Microwaveassisted

extraction

2)Dilution

3) Filtration

4)Ultrafiltration

5)HPLC- ICP-MSanalysis

2.0gliquid0.2gpowder

(50mLultra-purewater)

5µmcelluloseacetate0.45µmPVDF

10kDa,10000rpm,10min

ICS5000+(Thermo Scientific) iCAP Q(Thermo Scientific)

Samplepreparation

10mLHNO3 1%(m/m),H2O2 3%(m/m)

30minat90�C

q  FoodismainsourceofCrexposure

q  Therearenomaximumlevels(MLs)forchromiuminfood

q  Cr(VI)hasbeenclassifiedforalongMmecarcinogenictohumansbyinhalaMon(IARC,2012);

q  Cr(III)haslongbeenconsideredanessenMalnutrientforhumanhealthbutEFSAPanelin2014consideredthatthereisnoconvincingevidence

ofbeneficialeffectsassociatedwithchromiumintakeinhealthysubjects

I.2.SpeciaMonanalysisofchromium(CrIII-CrVI)

Increasingmolecularmassandcomplexity

INORGANICCOMPOUNDSAND

COMPLEXESNispecies:Ni0,NiO,NiCl2,NiSO4,NiCO3Ti species:Ti,TiCl4,TiO2Nanoparticles

ELECTRONICANDREDOXSTATESSe(IV)/Se(VI)As(III)/As(V)Cr(III)/Cr(VI)Fe(II)/Fe(III),…

STABLEISOTOPES

ORGANOMETALLICCOMPOUNDS

MACROMOLECULARCOMPOUNDSANDCOMPLEXES

ORGANICCOMPLEXES

MLn

ChallengesintermsofchromiumspeciaMoninfoodstuff

q  Bothchromiumspeciesareverylabile⇒theymayoxidase(CrIII→CrVI)orreduce(CrVI→CrIII)dependingontheredoxproperMesofthe(foodstuff)matrix

q  Eachspeciesisstableindifferentmedia(pH)hencemakingtheirsimultaneouslydeterminaMonatrulyanalyMcalchallenge

SpeciaMonanalysisofchromiuminfoodisgenerallycarriedoutsequenMallybyfocusingononespeciesataMme.

Themaindisadvantageofconven,onalspecia,onanalysismethodsistheimpossibilitytoassessthespecia,ondegrada,on(ifthecase).

ControversyrelatedtochromiumspeciaMoninfoodstuffs

q  EFSAstatesthatin(most)foodstuffCrispresentasCr(III)(EFSA,2014).

q  SomeauthorsreportedthepresenceofCr(VI)infood(Soaresetal.,J.Agric.FoodChem.,2010).

q  33-73%ofCr(VI) (ofCrtotal) in toastbread→Cr(III) oxidaMonduring toasMng??? (Mathebula;

(FoodChem.,2017).

Sateoftheart(simultaneous)speciaMonanalysisofchromium⇒speciesspecificisotopediluMon

q  IDMSistheonlyprimarymethodnowadaysavailablethatcanbeappliedtotraceandultra-traceanalysis.

q  TheequilibraMonoftheanalytewiththespikeisprimordialforachievingthemaximumaccuracy⇒parMallossoftheanalytea}erequilibraMon

ofthespikewiththesamplewillnotinfluencetheaccuracyofthedeterminaMon.

PrincipleofisotopediluMon

Themaindisadvantageofconven,onalspecia,onanalysismethodsistheimpossibilitytoassessandcorrectthespecia,ondegrada,on(ifthecase).

PhDproject(2018-2021):Ultra-tracespeciaMonanalysisofchromiuminfoodstuffbyHPLC-ICP-MSusingspeciesspecificisotopediluMon(CHROSPID)

Principleofspecis-specificisotopediluMonappliedtoCr(III)andCr(VI)determinaMon

Ø  SS-IDMSistheonlyanalyMcalapproachcapabletoevaluatethespeciesinter-conversionandtocorrectmathemaMcallyforsuchtransformaMons.

Ø  SS-IDMSpermitspeciesquanMficaMonandassessmentoftheirinterconversioninthesameanalyMcalrun.

Ø  InaddiMon,parMallossoftheanalytea}erequilibraMonofthespikeandthesamplewillnotinfluencetheaccuracyofthedeterminaMon.

( )( ) ( )( )( ) ( )βWACWACα1WACWAC

βWACWACα1WACWACR VI

spikeVIspike

52VIspikexx

52VIx

IIIspike

IIIspike

52IIIspikexx

52IIIx

VIspike

VIspike

50VIspikexx

50VIx

IIIspike

IIIspike

50IIIspikexx

50IIIxIII

50/52 ⋅⋅+⋅⋅+−⋅⋅+⋅⋅

⋅⋅+⋅⋅+−⋅⋅+⋅=

( )( ) ( )( )( ) ( )βWACWACα1WACWAC

βWACWACα1WACWACR VI

spikeVIspike

52VIspikexx

52VIx

IIIspike

IIIspike

52IIIspikexx

52IIIx

VIspike

VIspike

53VIspikexx

53VIx

IIIspike

IIIspike

53IIIspikexx

53IIIxIII

53/52 ⋅⋅+⋅⋅+−⋅⋅+⋅⋅

⋅⋅+⋅⋅+−⋅⋅+⋅=

( ) ( )( )( ) ( )( )β1WACWACαWACWAC

β1WACWACαWACWACR VI

spikeVIspike

52VIspikexx

52VIx

IIIspike

IIIspike

52IIIspikexx

52IIIx

VIspike

VIspike

50VIspikexx

50VIx

IIIs

IIIs

50IIIsxx

50IIIxVI

50/52 −⋅⋅+⋅⋅+⋅⋅+⋅⋅

−⋅⋅+⋅⋅+⋅⋅+⋅⋅=

( ) ( )( )( ) ( )( )β1WACWACαWACWAC

β1WACWACαWACWACR VI

sVIspike

52VIspikexx

52VIx

IIIspike

IIIspike

52IIIspikexx

52IIIx

VIspike

VIspike

53VIspikexx

53VIx

IIIs

IIIspike

53IIIspikexx

53IIIxVI

53/52 −⋅⋅+⋅⋅+⋅⋅+⋅⋅

−⋅⋅+⋅⋅+⋅⋅+⋅⋅=

WMm

=

HPLCseparaMon(anionexchange)

⇒  ColumnDionexIonPac™AG7:2mmx50mm(10μm)

⇒ Mobilephase:10mMHNO3+2.5%Methanol+0.32MEDTA(isocraMc)(pH=2)

⇒  ColumnTemperature:30°C

⇒Flow:0.20mL/min

SimultaneouscomplexaMonofCr(III)andCr(VI)

⇒  Cr(III)complexaMonwithEDTA(0,60mM)

⇒  Cr(VI)complexaMonwithdyphenylcarbazide(0,02mM)

⇒  pH=4

⇒  HeaMngat70°C(25min+25min)CrO4

2- + Cr3+ +

AnalyMcalprocedureforsimultaneousspeciaMonanalysisofCr(III)andCr(VI)

Cr3+ +

H2C

H2C

N

N

CH2

CH2

COO

COOHCH2 COOH

CH2 COO

-

-

H2C

H2C

N

N

CH2

CH2

COO

COO

CH2

CH2

COO

COO

Cr

-

+ 2H+

-

53Cr(VI)-DPC(5ppb)

50Cr(III)-EDTA(5ppb)

1. Complexation Cr(III)-EDTA

0,0 1,1 2,1 3,2 4,2

0,3 g

HNO3 MeOHEDTA

3. Separation4. ICP-MS detection

70ºC / 25min

Complexation 1 (DigiPrep)

70ºC / 25min.

Complexation 2 (DigiPrep)

EDTA[2,40 mM]

16 mL EDTA [0,9 g/l]

x

DPC[20,5 mM]

200 µL DPC[0,5 g/l]

HPLCThermoiCAP Q

2. Complexation Cr(VI)-DPC

5. Chromatogram

Cr(VI)-DPC

Cr(III)-EDTA

Volume= 20mL

xx x

x x

x

x

x

Cr(III) Cr(VI) x Cr(III)-EDTA x Cr(VI)-DPC

28

MethodvalidaMon⇒spikerecoveryexperiments

à  Infantformulamilk:Cr(III)natural

=3ppb;Cr(VI)spiked

:0.25ppb

à  Milkhalf-fat:Cr(III)natural

=5ppb; Cr(VI)spiked

:1ppb

à  Steakbeef:Cr(III)natural

=5ppb; Cr(VI)spiked

:0.5ppb

à  Bread:Cr(III)natural

=27ppb; Cr(VI)spiked

:5.0ppb

ProblemwithbreadspikedwithCr(VI):completeconversionofCr(III)toCr(VI)?

Bread:Cr(III)natural

=27ppb;Cr(VI)spiked

:5ppb

Cr(III)natural

=0ppb;Cr(VI)=32ppb(27+5)

analysis

InwaterwiththeaddiMonofCrspecies,interconversionoccursinbothdirecMons,whileinfoodmatricesthereistheconversionofCr(III)toCr(VI).

Cr(III)andCr(VI)inawaterstandardsoluMon

α=31%

β=16%

Cr(III)andCr(VI)added

infoodstuff

α=0%

β=100-150%

AnalyMcalfiguresofmerit

Cr(III)

Parameter1 2 3 4 5 6

Spikinglevel(µg/kg)0,013 0,024 0,048 2,70 4,41 4,67

Recovery(%)108% 98% 98% 100% 87% 94%

RSD(%)*12% 8% 10% 10% 7% 3%

LOQ(ppb) 0.035

*5non-consecuMvedays(1month)

Cr(VI)

Parameter1 2 3 4 5 6

Spikinglevel(µg/kg)0,032 0,051 0,10 0,26 0,54 0,82

Recovery(%)87% 93% 85% 95% 93% 92%

RSD(%)*9% 8% 7% 16% 8% 13%

LOQ(ppb) 0.049

Accuracyprofiles

40%

50%

60%

70%

80%

90%

100%

110%

120%

130%

140%

0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0

Réc

upér

atio

n (%

)

Concentrations (ug.kg-1)

Profil d'exactitude Cr(III)

Recouvrement (justesse)Limite basse tolérance (%)Limite haute tolérance (%)Limite d'acceptabilité basse (%)

1 + λ

1 - λ

+

- β

Increasingmolecularmassandcomplexity

INORGANICCOMPOUNDSAND

COMPLEXESNispecies:Ni0,NiO,NiCl2,NiSO4,NiCO3Ti species:Ti,TiCl4,TiO2Nanoparticles

ELECTRONICANDREDOXSTATESSe(IV)/Se(VI)As(III)/As(V)Cr(III)/Cr(VI)Fe(II)/Fe(III),…

STABLEISOTOPES

ORGANOMETALLICCOMPOUNDS

MACROMOLECULARCOMPOUNDSANDCOMPLEXES

ORGANICCOMPLEXES

MLn

Organiccomplexes

Organomercury(MeHg)Organotin(TBT-DBT-TPhT-DOT)Organoarsenic(MMA, DMA)OrganoleadOrganoselenium

…

As(III)/As(V)

Cr(III)/Cr(VI)

Sn(IV)

III.3.SpeciaMonanalysisoforganiccomplexes:mission(im)possible?

•  Dithiocarbamates(DTCs)-relaMvelyintenseusedasfungicidesbeingeffecMveagainstabroadspectrumofplantdiseases.

•  DespitethesignificantenvironmentalandfoodchainimpactofDTCs,thecurrentanalyMcalapproachesfortheirdeterminaMonsuffer

fromseriousdrawbacks.

•  TheEuropeanreferencemethodforthispurposereliesonnon-selecMvequanMficaMonbyindirectdeterminaMonofthesumofDTC

species(singleresiduemethod).

•  Thedevelopmentofamethodwithincreasedselec:vityforthedetermina:onofDTCsandoftheirdegrada:onproductsinfood(byamul:-approachstrategy)ishighlyneeded.

DTCs acidic

hydrolysis CS

2 Chromatographic

analysis

MulM-approachdeterminaMonofdithiocarbamatefungicidesandtheirdegradaMonproductsinfood

(H2020 – MSCA-IF MET-PEST)

DithiocarbamateFungicides

Thiram Ziram

Maneb

Me:ram Zineb

Ferbam

Propineb

MulM-approachanalyMcalstrategiesforDTCsdeterminaMon

Presence of a metal moiety (Fe, Zn

and/orMn) in theDTCs structure⇒

HPLCICP-MS

Thepresenceofsulphur

intheDTCsstructure⇒

HPLC-ICP-QQQMS

HPLC-MS/MS⇒targeMngDTCs

DeterminaMonoftheirdegradaMonproducts⇒verystable

Propineb

Propylene thiourea (PTU)

degradation

MainanalyMcalchallengeofDTCsdeterminaMon:lowstabilityandsolubility

Mainadvantage:

useofRP-HPLC-ICP-QQQMS

insteadofHILIC

(asfortheDTCs

MainanalyMcalparametersforthedeterminaMonofDTCsdegradaMonproducts(ETU,PTU)and

inrganicsulfurbyRP-HPLCcoupledtoICP-QQQMS

(firstICP-MSbasedmethod…)

HPLCcolumn Aqua®3µmC18,125Å;150×2mm

MobilePhase 5%MeOH,isocraMceluMon

Flow(mL/min) 0,25

Monitoredsignals [32]S→[48]SO;[34]S→[50]SO

MethodValidaMon⇒acuracyprofileapproach

LOQ=15ppb

Intermediateprecision:2-10%(dependingonthespikinglevel)

LOQ=10ppb

Intermediateprecision:1-8%(dependingonthespikinglevel)

Matricestested(spiking) Tomatoes,Grapes,Strawberries,Cherries

Spikinglevels(ppb) 10–400(6differentlevels)

ExtracMonsolvent Aqueous5%MeOH

ExtracMonprocedure SurfaceextracMon(wholefruit)(30min)

Recovery(%) 71-110

Linearrangetested(ng/mL) 10–1000

Linearity(r2) 0,9999–1,000

BackcalculatedconcentraMons 95–105%

Instrumentalprecision(%RSD) <2%

AnalyMcalfiguresofmerit

Chromatogramsobtainedfortheanalysisofreal-lifespikedsamples(wholefruits)

ETU PTU

Unidentified S-containing compound(s)

Strawberries

Grapes

ETU PTU

Unidentified S-containing compound(s)

FUTURESPERSECTIVESINTERMSOFSPECIATIONANALYSISINFOODPRODUCTS

q  Thespecieswhich(sMll)posean“official”interestintermsoffoodare:

MeHg,As(III)-As(V)andCr(III)-Cr(VI)

q  TheaccuratedeterminaMonofinorganicAsissMllchallenginginfisheryproducts(becauseofthelow

levelsofAsiandthematrixcomplexity)

q  MoreanalyMcaldevelopmentsmustbecarriedforthesimultaneousspeciaMonanalysisofCr(III)and

Cr(VI)byspeciesspecificisotopediluMoinfoodstuffs

q  An intersMngperspecMve is thespeciaMonanalysisoforganiccontaminantscontainingheteroatoms

(S,Cl,Br,…)byexploiMngthenewanalyMcalfeaturesprovidedbyICP-QQQMS.

GrazieperlavostraawenMone!