Multi-residue contaminants and pollutants analysis in saffron spice by stir bar sorptive extraction and gas chromatography–ion trap tandem mass spectrometry

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  Multi-residue contaminants and pollutants analysis in saffron spice by stir bar sorptive extraction and gas chromatography–ion trap tandem mass spectrometry
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   Journal of Chromatography A, 1209 (2008) 55–60 Contents lists available at ScienceDirect  Journal of Chromatography A  journal homepage: www.elsevier.com/locate/chroma Multi-residue contaminants and pollutants analysis in saffron spice by stir barsorptive extraction and gas chromatography–ion trap tandem mass spectrometry Luana Maggi a , Manuel Carmona a , C. Priscila del Campo a , Amaya Zalacain a , Jorge Hurtado de Mendoza b ,Francisco A. Mocholí b , Gonzalo L. Alonso a , ∗ a Cátedra de Química Agrícola. E.T.S.I. Agrónomos, Universidad Castilla-La Mancha, Campus Universitario, 02071 Albacete, Spain b Sailab, Parc tecnológic del Vallès, Argenters, 5 Ed. I. Bajos D, 08290 Cerdanyola del Vallès, Spain a r t i c l e i n f o  Article history: Received 19 June 2008Received in revised form 3 September 2008Accepted 8 September 2008Available online 12 September 2008 Keywords: SBSEMulti-residue pollutantsSaffronGC/MS/MS a b s t r a c t A method for the simultaneous determination of 46 semi-volatile organic contaminants and pollutantsinsaffronhasbeendevelopedforthefirsttimeusingastirbarsorptiveextractiontechniqueandthermaldesorptionincombinationwithgaschromatography–iontraptandemmassspectrometry.Theanalyticalmethod proposed was easy, rapid and sensitive and showed good linearity, accuracy, repeatability andreproducibility over the concentration range tested. Moreover, the correlation coefficients were higherthan0.98foralltargetcompoundsanddetectionlimitswerelowerthan1  g/kgexceptforsimazine.Thepresent method was also applied for the analysis of trace contaminants in saffron samples.© 2008 Elsevier B.V. All rights reserved. 1. Introduction Spices are mainly used in foods but also as raw materials forpharmaceuticalpreparations(Galenicproducts)[1].Plantsaresus- ceptibletoinsectandpestattacks,sopesticidesarewidelyusedfortheir protection. But this should not be the case of saffron, as onlyherbicides are used from time to time to protect bulb growth. TheonlyreferencesfoundontheuseofherbicidesconfirmthatinSpain[2],themostsalientproducerofqualitysaffron,theseproductsarenot usual due to the predominantly dry farming crops, e.g. vine-yardsandolives.Inareaswherethereareirrigatedlands,theuseof pesticides like herbicides (triazines) and insecticides (such as hex-achlorocyclohexanes (HCHs), chlorpyrifos and diazinon) is helpedalong.Thesecancontaminateothercropsbothatgroundwaterandenvironmental level. Herbicides are used in other countries suchas Greece, where simazine and atrazine are recommended as mosteffective [3], although such products are not allowed by the Euro- pean Union (EU).Most organic contaminants and pollutants bioaccumulate dif-ferently and present low rates of biodegradation, being in mostcases a risk to the environment and consumers health. It is worthpointing out that some of these products and their metabolites ∗ Corresponding author. Tel.: +34 967 599310; fax: +34 967 599238. E-mail address:  Gonzalo.Alonso@uclm.es (G.L. Alonso). may be found in these foodstuffs due to indirect contamination,i.e. they are used on other crops in areas adjacent to those of inter-est[1,4].Severalstudieshavebeencarriedoutindifferentcountries on spices and medical plants, but only one paper was found on theanalysis of pesticide residues in one saffron sample [1], although no analytical method optimisation was carried out.Until now there was no necessity to determine such contam-inants as it is also shown by the ISO/TS 3632 (2003) technicalspecification [5] which is the most exhaustive normative withregard to this spice and it does not include multi-residue analy-sis.Butrecentlysomesaffronsampleshavebeenintroducedinthemarket with a higher presence of contaminants and pollutants, itcan be a particular event but saffron consumers could be affected.Aswell,theEuropeanCommission(EC)hasdrawnupthemaximumresidue limits (MRLs) of pollutants for different products, includ-ing spices such as saffron [6]. In all products, MRL has not been specifically set, but it has to be lower than 0.01mg/kg.Another problem associated to these organic contaminants andpollutantsistheiranalysis,althoughstirbarsorptiveextractionhasbeen revealed as a powerful technique for their determination inwater [7,8], vegetables and fruits [9–11] but until now there are no availablemethodsinthescientificliteraturefortheirdeterminationin saffron matrices.The main objective of this study was to develop a method forthesimultaneousdeterminationof46multi-residuecontaminantsand pollutants in an aqueous saffron extract by stir bar sorptive 0021-9673/$ – see front matter © 2008 Elsevier B.V. All rights reserved.doi:10.1016/j.chroma.2008.09.026  56  L. Maggi et al. / J. Chromatogr. A 1209 (2008) 55–60 extraction (SBSE) and thermal desorption (TD) coupled to capil-lary gas chromatography–mass spectrometry (GC/MS). Full-scanand MS/MS monitoring mode in the detection step were also used.To confirm its practical application, 27 saffron samples have beenanalysed with the proposed method. 2. Experimental  2.1. Chemicals and reagents Analytical grade methanol was purchased from Merck (Darm-stadt, Germany), sodium sulphate anhydrous from Panreac(Barcelona, Spain). Water was purified through a Milli-Q System(Millipore, Bedford, MA, USA).  2.2. Standard solutions Polycyclic aromatic hydrocarbons (PAHs) (acenaphthy-lene, fluorene, anthracene, phenanthrene, pyrene, chrysene,benzo[ a ]anthracene,benzo[ b ]fluoranthene,benzo[ k ]fluoranthene,benzo[ a ]pyrene, indeno[1,2,3- cd ]pyrene, benzo[  ghi ]perylene,dibenzo[ a , h ]anthracene), a standard containing organochlorinepesticides (  -HCH,   -HCH,   -HCH,   -HCH, alachlor, heptachlor,metholachlor, aldrin, heptachlor epoxide isomer B,   -endosulfan,dieldrin,  p ,  p ′ -DDE,endrin,  -endosulfan,  p ,  p ′ -DDD,endosulfansul-fate, methoxychlor), triazines (simazine, atrazine, terbuthylazine,propazine, ametryn, prometrine, terbutryn), organophospho-rus pesticides (diazinon, fenchlorphos, chlorpyrifos, parathion,pendimethalin, sulprofos) and also molinate, pirimicarb andtrifluralin were purchased from Dr. Ehrenstorfer (Augsburg, Ger-many). [ 2 H 10 ]Phenanthrene (phenanthrene- d 10 , [ 2 H 12 ]chrysene(chrysene- d 12 ) and [ 2 H 12 ]benzo[ a ]pyrene (benzo[ a ]pyrene- d 12 )were used as internal standards and also purchased from Dr.Ehrenstorfer (Augsburg, Germany).Spikedsolutionswerepreparedbyaddingalltargetcompounds,together with the internal standards (IS), into an aqueous solutionof saffron (1g/L) to which 20% sodium sulphate anhydrous wasadded.  2.3. Samples According to Directive CEE 2092/91 [12], a biological saffron belongingtocommercialcategoryIaccordingtoISO/TS3632(2003)[5]wasusedasreference.Blankexperimentswerecarriedoutusingthis sample, as well as for method validation.Twenty-seven samples of saffron suspected to be contami-nated by pollutants were collected. All samples were analysed bytriplicates with the proposed SBSE method followed by TD andGC/MS/MS.  2.4. Extraction procedure A 100mL volume of a saffron aqueous solution (1g/L) con-taining 1mL of methanol, 20g of sodium sulphate anhydrousand 50  L methanolic solutions of ISs (100ng/L) were preparedfor analysis. The commercial polymethylsiloxane (PDMS) coatedstir bars (0.5mm film thickness, 20mm length, Twister, Gerstel,Mülheim and der Ruhr, Germany) were employed. The sam-ples were stirred at 1000rpm at room temperature for 14h[13]. The stir bar was then removed from the sample, rinsedwith distilled water and dried with a cellulose tissue, andlater transferred into a thermal desorption tube for GC/MS/MSanalysis.  2.5. SBSE desorption unit  The stir bars contained into the stainless steel tubes were des-orbedusingathermaldesorptionsystemPerkinElmerTurboMatrixATD (Norwalk, CT, USA). The thermal desorption conditions wereas follows: oven temperature, 290 ◦ C; desorption time, 5min; coldtraptemperature, − 7 ◦ C;Heinletflow,45mL/min.Theunitdesorp-tion was coupled to a gas chromatograph.  2.6. GC/MS equipment  The gas chromatograph (Varian CP-3800, Palo Alto, CA, USA)was equipped with a Saturn 2200 ion trap mass spectrometerand provided with a fused silica Factor Four capillary column (5%phenyl+95% dimethylpolysiloxane; 30m × 0.25mm ID; 0.25  mfilm thickness VF-5MS; Varian, Palo Alto, CA, USA). The chromato-graphic program was set at 50 ◦ C (held for 2min), raised to 180 ◦ Cat 20 ◦ C/min (held for 10min) and to 225 ◦ C at 3 ◦ C/min and thento 310 ◦ C at 5 ◦ C/min maintained for 5min; injector temperature,280 ◦ C; transfer line at 280 ◦ C; detector temperature, 200 ◦ C; Hecarrier gas flow, 1.0mL/min.  2.6.1. MS detection parameters: ion preparation and analysisScan function . All compounds, except benzo[ b ]fluoranthene,benzo[ k ]fluoranthene, benzo[ a ]pyrene, indeno[1,2,3- cd ]pyrene,benzo[  ghi ]perylene, dibenzo[ a , h ]anthracene and benzo[ a ]pyrene- d 12 , have been identified and quantified using this function(Table 1). MS/MS . As the last seven PAHs, including also benzo[ a ]pyrene- d 12 , one of ISs are not appropriately quantified, the MS/MS modehas been set for their determination (Table 2). The MS/MS condi- tionsusedfortheseanalyteswereasfollows:solventdelay:2min;peakthreshold:0;backgroundmass:40 m /  z  ;radiofrequencydumpvalue: 650 m /  z  ; filament current: 80  A; target TIC: 5000; maxi-mum ionization time: 25 ms; prescan ionization time: 1500  s;scan time: 0.50s/scan; multiplier offset:  ± 200V. The precursorions were isolated using a 3 m /  z   window and subjected to furthercollision-induced dissociation.  2.7. Analytical method validation Asreferencematerialdoesnotexist,biologicalsaffronhasbeen.Forlinearitystudy,calibrationgraphswereestablishedwithsaffronaqueoussolution(1g/L)spikedwithsixdifferenttargetcompoundconcentrations(10–30–50–100–200–500  g/kg).Eachlevelofcon-centrationwasanalysedtwicewithtwodifferentstirbars,givingatotaloffourreplicates.Thedetectionandquantificationlimits(LODand LOQ, respectively) were calculated by 3 and 10 signal to noiseratios, from a standard solution of 10  g/kg. Four replicate mea-surements were analysed with the proposed method to determinerepeatability, and these results have been compared with thoseobtained on 3 different days (reproducibility) [14]. 3. Results and discussion  3.1. SBSE extraction ItisthefirsttimethatSBSEwasappliedtosaffronandexcellentresults were obtained. To check the matrix effect, the calibrationcurves have been carried out both in water and saffron aqueoussolutions. No significant differences were observed for the targetcompounds, unlike other studies carried out on wines [13,15]. For thesereasons,thefinalcalibrationcurveshavebeencarriedoutonbiological saffron. Parameters such as extraction time or salting-outhavebeenstudiedtoincreasecompoundsextraction.Different  L. Maggi et al. / J. Chromatogr. A 1209 (2008) 55–60  57  Table 1 Retention time, EI full-scan ions selected for compounds identification and quantification, limit of detection and quantification (  g/kg) and correlation coefficients ( r  2 ) of calibration curves (from 10 to 500  g/kg) for the target compounds in saffronCompounds Retention time (min) Compound ion a ( m /  z  ) LOD (  g/kg) LOQ (  g/kg)  r  2 Polycyclic aromatic hydrocarbonsAcenaphthylene 8.91  152 , 153, 151 0.14 0.47 0.997Fluorene 10.22  165 , 166, 167 0.07 0.23 0.990Anthracene 13.39  178 , 176, 152 0.05 0.17 0.998Phenanthrene 13.63  178 , 176, 152 0.07 0.23 0.999Pyrene 24.11  202 , 200 0.08 0.27 0.999Chrysene 34.80  228 , 226 0.07 0.23 0.995Benzo[ a ]anthracene 35.06  228 , 226 0.06 0.20 0.991Benzo[ b ]fluoranthene 41.65 MS/MS 0.07 0.23 0.998Benzo[ k ]fluoranthene 41.83 MS/MS 0.09 0.30 0.994Benzo[ a ]pyrene 43.26 MS/MS 0.12 0.40 0.999Indeno[1,2,3- cd ]pyrene 48.13 MS/MS 0.13 0.43 0.996Dibenzo[ a , h ]anthracene 48.34 MS/MS 0.10 0.33 0.984Benzo[  ghi ]perylene 49.06 MS/MS 0.09 0.30 0.997Organochlorine pesticides  -HCH 11.61  181 ,  183 , 217, 219 0.23 0.77 0.991  -HCH 12.52  181 ,  183 , 217, 219 0.16 0.53 0.988  -HCH 12.79  181 ,  183 , 217, 219 0.08 0.27 0.993  -HCH (lindane) 14.04  181 ,  183 , 217, 219 0.11 0.37 0.987Alachlor 15.80  160 ,  188 , 132 0.13 0.43 0.987Heptachlor 16.18  270 ,  272 , 337, 237 0.10 0.33 0.993Metholachlor 18.46  162 ,  238 , 240 0.06 0.20 0.989Aldrin 18.59  263 ,  265 ,  261 , 293 0.06 0.20 0.994Heptachlor epoxide 21.57  353 ,  355 ,  351 , 263 0.31 1.03 0.996  -Endosulfan 24.31  241 ,  243 , 265, 339 0.29 0.97 0.999Dieldrin 26.30  261 ,  263 , 277, 237 0.10 0.33 0.999  p ,  p ′ -DDE 26.32  316 ,  318 , 246, 248 0.19 0.63 0.986Endrin 27.74  243 ,  245 ,  261 ,  263  0.29 0.97 0.999  -Endosulfan 28.65  241 ,  243 , 265, 339 0.09 0.30 0.999  p ,  p ′ -DDD 29.30  235 ,  237 ,  165 , 199 0.21 0.70 0.990Endosulfan sulfate 31.33  387 ,  272 ,  239 , 389 0.64 2.13 0.991Methoxychlor 35.76  227 , 228 0.22 0.73 0.983TriazinesSimazine 11.79  186 ,  201 , 203, 173 1.15 3.83 0.989Terbuthylazine 12.34  215 , 217, 200, 173 0.12 0.40 0.983Atrazine 12.39 229,  214 , 216, 173 0.32 1.07 0.988Propazine 12.91  229 ,  214 , 187,  172  0.13 0.43 0.994Ametryn 16.36  227 ,  212 , 185, 170 0.27 0.90 0.984Prometrine 16.64 241,  226 , 199, 184 0.04 0.13 0.989Terbutryn 17.54 241,  226 , 185,  170  0.10 0.33 0.987Organophosphorus pesticidesDiazinon 13.04  304 , 199,  179 , 137 0.08 0.27 0.992Fenchlorphos (ronnel) 16.40  287 ,  285 , 125, 109 0.54 1.80 0.984Chlorpyrifos 18.63  316 ,  314 , 258, 197 0.22 0.73 0.997Parathion 19.31  291 , 155, 139,  109  0.06 0.20 0.989Pendimethalin 21.20  252 , 191, 162 0.39 1.30 0.987Sulprofos 30.58 324,  322 ,  156 , 139 0.56 1.87 0.980Other pesticidesTrifluralin 10.87  306 , 290,  264  0.04 0.13 0.997Molinate 9.63  126 , 98 0.25 0.83 0.992Pirimicarb 14.26 238,  166 , 72 0.07 0.23 0.997Internal standardsPhenanthrene- d 10  13.27  188 , 189, 160, 159Chrysene- d 12  34.93  240 , 236Benzo[ a ]pyrene- d 12  43.62 MS/MS a Ion used for compounds identification. Bold  m /  z   was selected for compounds quantification. extractiontimeshavebeentested(8,14and24h)(datanotshown)andtheoptimumexposuretimeforsaffronsampleshasbeenestab-lished at 14h, as a compromise between efficiency and run time,because full equilibrium is not essential for accurate quantifica-tion[16].Thesalting-outeffectonthesignalimprovementhasalso been evaluated by adding different amounts of sodium sulphateanhydrous (0, 100 and 200g/L). The higher ionic strength (200g/L of sodium sulphate anhydrous) increases the signal intensitiesfor triazines and HCHs, while the non-polar compounds such asPAHs show lower extraction efficiency, although their sensitiv-ity and detectability have been improved by using the MS/MSdetection mode. Moreover, the effect of methanol addition onoptimisation of extraction has been studied by adding differentpercentages of methanol (0, 1 and 10%). An addition of 10% con-siderably reduced the adsorption of PAHs and the extraction of themorepolarcompoundsalsodecreasedto10%methanolbecausethedistribution constant  K  PDMS/water  for polar compounds decreaseswhen the methanol constant increases. On the contrary, the addi-tion of 1% slightly improved the extraction, so it could be a goodcompromise.  58  L. Maggi et al. / J. Chromatogr. A 1209 (2008) 55–60  Table 2 GC/MS/MS parameters for compounds identificationCompounds Precursor ion ( m /  z  ) Product ion ( m /  z  ) Excitation storage level ( m /  z  ) Excitation amplitude (V)Benzo[ b ]fluoranthene 252 250 90 2Benzo[ k ]fluoranthene 226 (25%)Benzo[ a ]pyreneBenzo[ a ]pyrene- d 12  264 260 90 2236 (25%)Indeno[1,2,3- cd ]pyrene 276 274 90 2Benzo[  ghi ]perylene 252 (<10%)Dibenzo[ a , h ]anthracene 278 276 90 2252 (<10%)  Table 3 Repeatability, reproducibility (expressed as % RDS) and accuracy (%) calculated at 10  g/kg levels for the target compoundsCompound Repeatability (%) Reproducibility (%) Concentration (  g/kg) Accuracy (%)Polycyclic aromatic hydrocarbonsAcenaphthylene 11.4 15.4 9.5 95.3Fluorene 11.2 14.7 10.1 101.1Anthracene 11.9 13.0 10.3 103.1Phenanthrene 13.5 12.3 10.0 100.2Pyrene 13.1 13.3 9.1 90.7Chrysene 11.8 18.8 11.7 116.8Benzo[ a ]anthracene 14.4 17.9 12.4 124.0Benzo[ b ]fluoranthene 18.2 18.3 9.7 97.1Benzo[ k ]fluoranthene 16.4 18.8 9.7 97.2Benzo[ a ]pyrene 21.4 20.2 9.8 97.6Indeno[1,2,3- cd ]pyrene 16.9 19.7 7.9 79.1Dibenzo[ a , h ]anthracene 18.1 18.6 7.9 78.6Benzo[  ghi ]perylene 17.8 17.8 7.6 75.9Organochlorine pesticides  -HCH 3.6 9.6 10.4 103.7  -HCH 8.5 14.8 10.2 101.9  -HCH 13.4 14.2 10.2 102.3  -HCH (lindane) 14.4 15.5 10.8 108.0Alachlor 12.3 13.8 11.0 110.1Heptachlor 12.1 13.0 11.1 111.4Metholachlor 15.8 14.6 8.6 85.8Aldrin 13.7 14.6 10.3 103.4Heptachlor epoxide 11.1 13.7 8.2 82.5  -Endosulfan 13.6 12.0 9.0 90.3Dieldrin 21.6 21.7 8.1 81.0  p ,  p ′ -DDE 11.5 14.3 8.1 80.6Endrin 14.9 15.3 8.2 81.8  -Endosulfan 17.9 18.7 8.0 80.3  p ,  p ′ -DDD 12.9 18.5 7.8 78.5Endosulfan sulfate 22.7 21.8 7.5 75.2Methoxychlor 9.7 15.9 7.6 75.8TriazinesSimazine 12.0 15.2 10.5 105.3Atrazine 16.1 14.1 9.5 94.6Terbuthylazine 13.1 13.0 9.6 96.3Propazine 12.3 12.0 8.3 83.0Ametryn 10.9 11.6 7.6 75.7Prometrine 12.7 14.1 9.2 92.2Terbutryn 11.7 11.7 10.2 102.1Organophosphorus pesticidesDiazinon 11.6 14.4 8.2 81.6Fenchlorphos (ronnel) 13.4 11.4 10.2 102.3Chlorpyrifos 17.0 22.0 7.5 75.4Parathion 3.9 9.9 8.5 85.3Pendimethalin 2.9 6.4 9.5 94.6Tetrachlorvinphos 10.3 13.3 9.1 90.5Sulprofos 9.6 12.7 7.8 77.6Other pesticidesTrifluralin 3.7 9.9 7.9 79.0Molinate 13.4 14.5 10.8 108.5Pirimicarb 7.4 10.4 7.8 77.7  L. Maggi et al. / J. Chromatogr. A 1209 (2008) 55–60  59 Other parameters such as sample volume were establishedaccordingtowatermatrixbibliography[13],where100mLofsam- plearerecommended.Thisparameterisalimitingfactorinseveralenvironmental samples, but it is not the case of saffron.These results show the efficacy of SBSE even if they cannot becomparedtootherextractiontechniquesforsaffronsincethisisthefirsttimethatamethodwasoptimisedtodeterminemulti-residuepollutants.  3.2. GC/MS detection SincetheSBSEpreparationofthesamplegivesahighsensitivityandthematrixeffectislow,itispossibletouseMSwithelectronicimpact (EI) in full-scan mode. Different families of semivolatilecompounds have been analysed (Table 1), and enables us to iden- tify and quantify the analytes below the MRL normative and alsogive us also the possibility of finding unknown substances in thesample.The resolution of the less volatile compounds, benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene, indeno[1,2,3- cd ]pyrene, benzo[  ghi ]perylene, dibenzo[ a , h ]anthracene,benzo[a]pyrene- d 12  (in the chromatogram, from 41.65 to49.06min) was not as good as expected; and for this reasonthe MS/MS acquisition mode was used and the optimized ener-gies and collision induced dissociations (CIDs) required for thedissociation of the seven PAHs are shown in Table 2.  3.3. Validation procedure The proposed multi-residue method for the analysis of 46organic contaminants and pollutants has been validated for saf-fron (Tables 1 and 3). The method showed a good linearity inthe range between 10 and 500  g/kg and the correlation coef-ficients were higher than 0.98 for all the analytes studied. Asshown in Table 1, the LODs were lower than 1  g/kg for all targetcompounds, with the only exception being simazine (1.15  g/kg)which has a low affinity to the apolar PDMS polymer. Also, LOQswere lower than 1  g/kg for the tested compounds except forheptachlor epoxide (1.03  g/kg), endosulfan sulphate (2.13  g/kg),atrazine (1.07  g/kg), fenchlorphos (1.80  g/kg), pendimethalin(1.30  g/kg), sulprofos (1.87  g/kg) and simazine (3.83  g/kg). Inaddition,itisnecessarytopointoutthatallLODsandLOQsobtainedare lower than the MRLs set by the EC. These data confirm theefficacy of SBSE coupled to GC/MS/MS for the determination of multi-residue pollutants in saffron although they cannot be com-pared with others because there was not paper on it.Table 3 shows the results obtained for repeatability, repro-ducibility and accuracy expressed as % RDS calculated at 10  g/kglevels for the target compounds. The values for repeatabilityshowed the precision of the method at 10  g/kg with mean valuesranging between 2.9 (pendimethalin) and 22.7% (endosulfan sul-phate). Results for reproducibility were noteworthy and indicatedthe robustness of the extraction method with mean values of RDSaround 15% for 100mL at 10  g/kg. These parameters showed thatSBSE procedure is valid for saffron.  3.4. Application to saffron samples The proposed method was applied to 27 saffron samples sus-pected of contamination. The data (Table 4) show that the samples contained different levels of contaminants but, even more worri-some,isthefactthatsomeofthemhavehigherconcentrationsthanthe established MRLs.The predominant compounds detected in the analysedsamples were PAHs, especially benzo[ b ]fluoranthene, benzo[ k ]fluoranthene, benzo[ a ]pyrene and dibenzo[ a , h ]anthracene. Nine  Table 4 Concentration (  g/kg) of multi-residue pollutants detected in 27 samples of saffron analysedCompound Number of samples contaminated Mean concentration of contaminants (  g/kg) ± SD MRL  a (  g/kg)Polycyclic aromatic hydrocarbonsBenzo[ b ]fluoranthene 7 1.4  ±  0.6 10.0Benzo[ k ]fluoranthene 8 17.0  ±  5.6 10.0Benzo[ a ]pyrene 9 14.5  ±  4.0 10.0Benzo[  ghi ]perylene 1 7.0  ±  2.8 10.0Indeno[1,2,3 -cd ]pyrene 1 96.0  ±  7.9 10.0Dibenzo[ a , h ]anthracene 6 8.1  ±  1.3 10.0Organochlorinated pesticides  -HCH 6 59.0  ±  20.0 10.0 b  -HCH 3 22.0  ±  8.0 10.0 b  -HCH 1 29.7  ±  1.0 20.0 b  -HCH 2 35.0  ±  10.0 50.0Alachlor 4 14.0  ±  6.0 100.0Heptachlor 1 3.0  ±  0.7 100.0 c  -Endosulfan 3 25.4  ±  6.7 100.0 d TriazinesSimazine 6 145.0  ±  60.0 10.0Atrazine 2 44.1  ±  4.2 100.0Propazine 1 54.0  ±  3.5 10.0Ametryn 1 7.7  ±  0.5 10.0Organophosphorus pesticidesDiazinon 8 31.0  ±  12.0 20.0Chlorpyrifos 4 41.0  ±  20.0 100.0Sulprofos 1 47.0  ±  1.5 10.0Other pesticidesMolinate 1 31.5  ±  5.6 100.0 a Directive 149/2008/CE. b Total of the isomers except for  -isomer. c Total of heptachlor and heptachlor epoxide expressed as heptachlor. d Total of   and  -endosulfan and endosulfan sulfate expressed as endosulfan.
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