Application of solid-phase microextraction in the monitoring of priority pesticides in the Kalamas River (N.W. Greece)

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1 Journl of Chromtogrphy A, 963 (2002) locte/ chrom Appliction of solid-phse microextrction in the monitoring of priority pesticides in the Klms River (N.W. Greece) b Dimitr A. Lmbropoulou, Vsilios A. Skks, Dimitr G. Hel, Trintfyllos A. Albnis, * Deprtment of Chemistry, University of Ionnin, Ionnin 45110, Greece b Deprtment of Frm Orgniztion nd Mngement, University of Ionnin, Agrinio 30100, Greece Abstrct A solid-phse microextrction (SPME) method ws pplied to n extended monitoring survey of priority pesticides for the Europen Union for period of 12 months in wter of the Klms River (Epirus region of northwestern Greece) in order to determine their concentrtions nd sesonl vritions. Polydimethylsiloxne-coted fiber (100 mm) ws used. The smples were screened using gs chromtogrphy with flme thermionic detection. Detection ws confirmed by gs chromtogrphy mss spectroscopy. The most frequently detected pesticides were some of the more commonly used herbicides, such s S-ethyl-N,N-di-n-propylthiol crbmte (EPTC), triflurlin, trzine, deethyltrzine, terbuthylzine nd lchlor, nd insecticides, such s crbofurn, dizinon, disulfoton, prthion methyl, prthion ethyl, fenthion nd ethion. Concentrtions of individul compounds rnged from to 0.3 mg/ L. Greter pesticide concentrtions occurred during the sesons of ppliction. A comprison with well-estblished solid-phse extrction (C18 disks) procedure ws performed for smples of high-seson ppliction (My September) in order to confirm the effectiveness of the SPME technique. The results demonstrte the suitbility of the SPME method for routine screening multiresidue nlysis in nturl wters Elsevier Science B.V. All rights reserved. Keywords: Wter nlysis; Environmentl nlysis; Pesticides 1. Introduction resulting in mny environmentl monitoring progrms for brod rnge of pesticides [1]. Pesticide contmintion of surfce nd ground Studies involving the determintion of pesticides wter resulting from griculturl use hs been well in environmentl mtrices often del with smples documented round the world. The widespred use with low nlyte concentrtions contining lrge of pesticides for griculturl nd non-griculturl number of interfering compounds. Thus, simple nd purposes hs resulted in the presence of their res- highly sensitive nlyticl techniques re required to idues in vrious environmentl mtrices. Thus, pest- detect nd quntify pollutnts in wter t trce levels icide residue nlysis in environmentl smples hs [2]. received incresing ttention in the lst few decdes, The determintion of pesticides by chromtogrphic techniques requires extensive nd time-consuming smple preprtion, prior to finl concen- *Corresponding uthor. Tel.: ; fx: trtion. This usully includes n extrction step E-mil ddress: tlbnis@cc.uoi.gr (T.A. Albnis). [liquid liquid extrction (LLE), supercriticl fluid / 02/ $ see front mtter 2002 Elsevier Science B.V. All rights reserved. PII: S (02)

2 108 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) extrction (SFE) or solid-phse extrction (SPE)] s well s clen-up procedure in order to obtin finl extrct fully comptible with the chromtogrphic determintion [3 6]. In the lst few yers, severl uthors hve reported the requirement for mjor simplifiction of smple preprtion, with minituriztion of scle, which will result in reduction in nlysis time nd solvent consumption [7,8]. Solid-phse microextrction (SPME), developed by Pwliszyn nd co-workers [9,10], is recent smple preprtion technique tht is proving incresingly useful in nlyticl chemistry nd tht presents some of the chrcteristics outlined bove for new smple preprtion strtegy. The method elimintes the use of orgnic solvents, hs the dvntge of simplicity nd integrtes smpling, extrction, concentrtion nd smple introduction into single solvent-free step [9]. SPME hs been employed successfully in the nlysis of wide rnge of pollutnts, such s BTEX (benzene, toluene, ethylbenzene nd xylenes) [11], polycyclic romtic hydrocrbons (PAHs) [12] nd polycyclic biphenyls [13]. Pesticides hve lso been determined by SPME in different mtrices, such s wine [14], fruits [15], soils [16], honey [17,18], biologicl fluids [19] nd queous smples [8,20]. Fig. 1. Smpling sttions long the course of the Klms River. This work presents the results of n extensive monitoring survey tht ws crried out for period Klms River. The Klms River (96 km long), of one yer in the Klms River (Epirus region, with few tributries, ctchment re of c northwestern Greece) using SPME coupled to GC. km, nd with men nnul flow-rte of 54 m /s, The min objectives of this study were: (1) to dischrges into the Ionin Se (Fig. 1). Agriculture demonstrte the pplicbility of the proposed method nd mixed frming re the mjor economic ctivities for rpid nd ccurte screening multiresidue pest- in the re of study nd the min cultivtion includes icide nlysis in environmentl wter smples, (2) to mize, sorghum, cerels, lflf, vegetbles, monitor the occurrence of wide rnge of pesticides pottoes, citrus fruits nd olives. belonging to different chemicl groups, routinely pplied in the bsin of the Klms River, nd to determine their temporl nd sptil vritions in 3. Experimentl river wter smples, nd (3) to ssess the surfce wter qulity of the Klms River with respect to 3.1. Smpling potentil pesticide contmintion t selected sites. Wter smples were collected monthly from the min flow of the Klms River between Jnury 2. Are description nd December Six smpling sttions were selected in order to cover ll the possible pollution The pesticide survey ws conducted in 2000 t six sources of the Klms River (Fig. 1), locted ner different sttions (K1 K6) long the course of the points where tributries meet the min river course.

3 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) A 2.5 L volume of wter ws collected in glss lozolin] (Tble 1). These pesticides were chosen s bottles from ech smpling site t medium depth. trget nlytes on the bsis of being included in the After being filled with wter, the bottles were seled priority list of the Europen Union (EU), becuse of with screw cps lined with luminum foil. The their ppliction in the studied re, nd their bottles were stored in n ice-cooler t 4 8C, reching previously reported detection [24]. Thirteen of the 22 the lbortory on the sme dy, nd were normlly nlyzed pesticides were detected in the Klms extrcted within 48 h. River during the 12 month smpling survey. The nlysis of pesticides ws bsed on the SPME 3.2. Regents nd stndrds procedures described for ech pesticide chemicl group in previous works [25 28]. However, in the Pesticide nlyticl stndrd mterils were pur- present study the prmeters of the direct SPME chsed from Riedel-de Hen (Seelze, Germny). multiresidue nlysis were optimized s follows, in Stock stndrd solutions of 50 mg/l of ech com- order to obtin the best extrction performnce for pound were prepred in methnol nd were used for ll groups of trget nlytes: slt 15%, methnol the preprtion of mixture solution of the selected,0.1%, stirring rte 960 rpm, ph 7, nd n equilibcompounds t the required concentrtion. Methnol, rium time of 45 min. A 5 ml volume of wter dichloromethne nd ethyl cette were purchsed smple ws plced in 10 ml vil, which ws from Pestiscn (Lbscn, Dublin, Irelnd). Sodium seled with hole-cp nd PTFE-lined septum. chloride ws purchsed from Merck (Drmstdt, The smples were stirred before nd during ex- Germny). Empore extrction C18 disks (47 mm trction. The fibre ws then immersed in the queous I.D.30.5 mm) were purchsed from Vrin (Hrbor phse for 45 min with stirring t room temperture City, CA, USA). (2562 8C). After extrction, the fibre ws exposed directly to the hot injector of the GC system for 3.3. SPME fibres nlysis. Therml desorption of pesticides ws crried out for 10 min. After this period, no significnt SPME holder nd fibre ssemblies for mnul blnk vlues were observed. smpling were provided by Supelco (Bellefonte, PA, The nlysis of wter smples using SPE C 18 USA) nd used without modifiction. The fibre disks ws performed ccording to the methodology coting ssyed ws polydimethylsiloxne (PDMS, described by Albnis nd Hel [4]. 100 mm). Before mesurements the PDMS fibre ws conditioned in the injector for 3 h t 240 8C, with the 3.5. Quntifiction split vent open to fully remove ny contminnt tht might hve cused very high bseline noise nd lrge Quntifiction of the smples ws crried out by ghost peks. The fibre ws then repetedly injected pek re using the externl stndrd clibrtion. A into the GC system until interfering peks disp- clibrtion curve ws obtined with pesticide stnpered. During this desorption process the GC drds in the rnge from 0.05 to 10 mg/ L, extrcted column oven temperture ws mintined t 240 8C. under the sme conditions s the rel smples. The concentrtions of the detected pesticides were the 3.4. Anlyticl method verge vlues of three mesurements. Becuse the presence of orgnic solvents in the queous smples Wter smples were screened for 22 pesticides influences the extrction process, the sme methnol [herbicides: S-ethyl-N,N-di-n-propylthiol crbmte content (0.1%) ws dded to the rel smples in (EPTC), propchlor, metolchlor, lchlor, tri- order to normlize the influence of the methnol flurlin, simzine, trzine, terbuthylzine nd pro- concentrtion between spiked (clibrtion curves) metryne; insecticides: dizinon, disulfoton, prthion nd rel wter smples. methyl, prthion ethyl, fenthion, fenitrothion, eth- GC MS confirmtion in both the full-scn nd ion, bromophos ethyl, bromophos methyl, terbufos selected ion monitoring modes ws performed on the nd crborurn; fungicides: chlorothlonil nd vich- selected smples in order to determine the presence

4 110 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) Tble 1 Moleculr structure, moleculr mss, wter solubility, octnol wter coefficients nd soil sorption of trget compounds b Pesticide Moleculr Wter Log Kow Soil mss solubility sorption (mg/l) Herbicides EPTC Triflurlin Propchlor Simzine Atrzine Deethyltrzine (DEA) c Terbuthylzine Alchlor Prometryne Metolchlor Insecticides Terbufos Dizinon Disulfoton Prthion methyl Fenitrothion Fenthion Prthion ethyl Bromophos methyl Bromophos ethyl Ethion Crbofurn Fungicides Chlorothlonil Vichlozolin OSU Extension Pesticide Properties [21]. b Log K, octnol wter prtition coefficients from Ref. [22]. ow c From Ref. [23]. K oc of pollutnts. Pesticides in river wter smples re Scientific, Folsom, CA, USA). The temperture identified when the following criteri re met: the progrm used ws s follows: 55 8C (2 min) to chromtogrphic peks of both ions for the unknown 210 8C (21 min) t 5 8C/ min; then 210 8C to 270 8C nd the stndrd smple must coincide t the sme (0 min) t 10 8C/min. The injection temperture ws retention time nd the rtio between the two selected 240 8C. Helium ws used s the crrier gs (1.5 ions (Tble 2) must be the sme with tolernce of ml/min) nd mke-up gs (40 ml/min). The detec- 615%. tor gses were hydrogen nd ir, nd their flow-rtes were regulted t 120 nd 4.0 ml/min, respectively Gs chromtogrphic conditions The FTD ion source ws n lkli metllic slt (Rb2SO 4) bonded to 0.2 mm spirl of pltinum GC flme thermionic detection wire. Chromtogrphic nlysis ws performed using Shimdzu 14A cpillry gs chromtogrph GC MS equipped with flme thermionic detector (FTD). A QP 5000 GC MS system from Shimdzu, The DB-5 column used, 30 m30.32 mm I.D., equipped with cpillry column DB-5-MS, 303 contined 5% phenyl methylpolysiloxne (J & W 0.25 mm, 0.25 mm, contining 5% phenyl methyl-

5 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) Tble 2 Tble 3 Typicl frgment ions (m/z) of the trget pesticides in GC MS- Men detected pesticide concentrtions (mg/ L) nd rnge t six SIM sttions on the Klms River (K1 K6) in the period from Compound Jnury to December 2000 t R (min) m/z Pesticide Detection Concentrtion (mg/l) EPTC , 86 (%) Propchlor , 120 (n572) Men Detected DEA , 172 detected rnge Triflurlin , 264 Crbofurn , 149 Herbicides Simzine , 173 EPTC Atrzine , 215 DEA Terbuthylzine , 214 Triflurlin Terbufos , 97 Atrzine Dizinon , 137 Terbuthylzine Chlorothlonil , 264 Alchlor Disulfoton , 88 Insecticides Vinclozolin , 212 Crbofurn Alchlor , 160 Dizinon Prthion methyl , 109 Disulfoton Prometryne , 184 Prthion methyl Fenitrothion , 109 Prthion ethyl Metolchlor , 162 Fenthion Fenthion , 125 Ethion Prthion ethyl , 109 Bromophos methyl , 125 Bromophos ethyl , 97 Ethion , 231 compound] nd the obtined recoveries were bove 85% for ll pesticides in this type of wter (Tble 4). These pesticides re recommended for use on polysiloxne (J & W Scientific), ws used under the multiple crops in the Epirus re ccording to our following chromtogrphic conditions: injector tem- mrket survey nd they re reported to be reltively perture 240 8C, oven temperture progrmme 55 8C persistent with hlf-lives of up to 3 months [29]. For (2 min) to 210 8C (20 min) t 5 8C/ min nd to these resons it is not surprising tht multiple 270 8C t 10 8C/ min. Helium ws used s the crrier detections of these compounds were observed nd gs t 1.0 ml/ min. The interfce ws mintined t their concentrtions were the highest during the 290 8C nd the spectr were obtined t 70 ev. ppliction seson nd low-rinfll events. Triflurlin ws the most frequently detected herbicide with mximum concentrtion of 0.30 mg/l. 4. Results nd discussion Its occurrence ws observed throughout the whole survey period with the exception of the winter 4.1. Overview of pesticide detection months when dilution effects nd degrdtion reduced concentrtions to below the detection limit Tble 3 contins summry of the occurrence nd (Tble 5). concentrtions of the pesticides detected in smples The mximum concentrtions for trzine were collected during the 12-month study on the Klms observed in the period of My to June with River. Six herbicides of the chemicl groups tri- decresing tendency during the months fter field zines (DEA, trzine, terbuthylzine), cetmides ppliction (Tble 5). The trzine metbolite DEA (lchlor), dinitronilines (triflurlin) nd crbmtes ws found in 85% of the smples tht contined (EPTC) were detected. The SPME method used trzine nd lso in five smples where trzine ws llows the determintion of these compounds t very below the limit of detection. The men rtio of DEA low concentrtions [limits of detection (LODs) to trzine, DAR, ws estimted to be 0.4 to 0.7 t rnged from to mg/ L depending on the ech sttion during April September 2000 (Tble 5).

6 112 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) Tble 4 Limits of detection (LODs) nd reltive stndrd devitions (RSDs) for the GC FTD nd GC MS systems nd recoveries for the GC FTD system for the selected pesticides using PDMS 100 mm fiber Pesticide GC FTD GC MS LOD RSD Recovery LOD RSD (mg/l) (%) Klms River (%) (mg/l) (%) Herbicides EPTC Propchlor Triflurlin Simzine DEA Atrzine Terbuthylzine Alchlor Prometryne Metolchlor Insecticides Crbofurn Terbufos Dizinon Disulfoton Prthion methyl Fenitrothion Fenthion Prthion ethyl Bromophos methyl Bromophos ethyl Ethion Fungicides Chlorothlonil Vinchlozolin These results gree with those reported in other pplied s pre-plnting herbicide with soil incorpostudies [30,31], suggesting tht DEA is very rtion nd its residues cn be detected in runoff common detectble metbolite of trzine. In ddi- wters with the first rinfll events fter the dry tion, the presence of DEA in some wter smples seson [34]. could be ttributed to microbil degrdtion of the Alchlor ws determined t sttion K4 in the s-trizine herbicides in soil being trnsported in the middle of the river course during its ppliction dissolved phse by the river [32]. period in April with concentrtions bove 0.1 mg/l, Terbuthylzine ws only detected during the ppli- while low concentrtion of mg/ L ws found ction period (Mrch) t sttions K2 nd K3 t trce in lte August with the first rinfll events. Trces of concentrtions, showing tht this trizine is lso lchlor were found during these periods t sttions being pplied preferentilly to trzine nd simzine. K5 nd K6, probbly due to dilution effects, reflect- This preferentil use hs been reported for other ing regionl ppliction of the pesticide close to the regions with similr cultivtions [33]. smpling sttion (K4). EPTC ws detected in the period of the first With respect to insecticides, dizinon ws found t rinfll events from lte August to October with the highest levels (mximum concentrtion 0.25 mg/ men concentrtion of 0.60 mg/ L. This compound is L) compred to other insecticides t ll sttions

7 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) Tble 5 Men detected concentrtions (mg/ L) of pesticides in Klms River wter smples (K1 K6) in the period from My to September 2000 using SPME (PDMS, 100 mm) nd SPE (C disks) Pesticide Men detected concentrtion (mg/l)6rsd (%) 18 My June July Aug. Sep. SPME Herbicides EPTC DEA Triflurlin Atrzine Insecticides Dizinon Disulfoton Crbofurn SPE Herbicides EPTC DEA Triflurlin Atrzine Insecticides Dizinon Disulfoton Crbofurn (Tble 5). Dizinon is one of the most widely used insecticides in the re round the Klms River ccording to the unofficil reported usge by locl frmers. It is used for the control of insects in wide rnge of cultivtions s well s seed tretment for mize nd for insects nd pests in niml houses. Disulfoton ws the most frequently detected insecticide throughout lmost the whole period with the exception of the winter months t men detected concentrtion of 0.03 mg/l (Tble 5). Ethion nd prthion methyl were detected during the Spring period with men concentrtions of 0.02 nd 0.08 mg/ L, respectively, while prthion ethyl ws lso detected in the Summer months t men concentrtion of 0.01 mg/ L. Fenthion ws detected only twice t sttions K1 nd K4 t trce levels. This ws n expected result due to the fct tht fenthion is redily degrded in queous solutions. Its instbility in wter solution hs lredy been reported [5] nd its exclusion from the Ntionl Pesticide Survey (USA) list demon- strtes tht it is unstble in well wter over period of 14 dys. Crbofurn ws only detected t the Spring sm- pling during April My, which coincides with the period of field ppliction, nd the respective con- centrtions rnged from 0.03 to 0.15 mg/l Sesonl pttern of pesticide detection Sesonl trends were observed in the ppernce of pesticides in river wter smples. The sesonl vrition of the sum of the detected pesticides for ll smpling sttions is shown in Fig. 2. The highest levels occur during the period of pesticide ppliction nd sesonl pek is usully observed in lte September following the first rinfll events fter the dry Summer period. Low concentrtions were ob- served during the winter months becuse of dilution effects due to high-rinfll events. The decrese in rinfll in Summer results in n increse in pesticide

8 114 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) competing with possible dilution effects from sttion to sttion. 5. Comprison between SPME nd SPE Fig. 2. Sesonl vrition of the sum of concentrtions of the detected pesticides in wter smples of the Klms River t six smpling sttions (K1 K6) for the period from Jnury to December In order to check the effectiveness of the SPME technique, its performnce ws compred with tht of well-estblished conventionl procedure bsed on extrction of river wter smples, C18 SPE. The procedures were pplied to smples collected in the Spring nd Summer smpling t the sttions long the Klms River nd the pesticide concentrtions obtined re given s the men vlue for three replictes (Fig. 3). The men concentrtions determined by SPME nd SPE re shown in Tble 6. The obtined results demonstrte tht both tech- niques cn extrct the detected pesticides successful- ly. Generlly, SPE is more expensive nd time- consuming method, which mkes the SPME method more fvorble technique for trce nlysis work. concentrtions t this time of yer, in ddition to the fct tht the Summer period comes just fter their ppliction nd most pesticides hve soil hlf-lives of severl weeks. The vrition in pesticide contmintion does not follow the pttern of integrtion from the sources to the esturies s observed in previous reports for other river bsins of the Epirus [35]. The concentrtion rnges of the pesticides do not show lrge vrition long the course of the river, indicting tht new sources of pesticide residues contribute to their occurrence long the river course, 6. Conclusions This study shows clerly tht the combintion of SPME with GC FTD/ MS cn be used dvntge- Fig. 3. GC FTD chromtogrm of Klms River wter smple by PDMS 100 mm fiber (K1 sttion, June 2001). 15EPTC, 25DEA, 35triflurlin, 45trzine, 55dizinon.

9 D.A. Lmbropoulou et l. / J. Chromtogr. A 963 (2002) Tble 6 Sesonl vrition of the most frequently detected pesticides (triflurlin, trzine, DEA, dizinon, disulfoton) in wter smples of the Klms River t six smpling sttions (K1 K6) for the period from Jnury to December 2000 Concentrtion (mg/l) Jn. Feb. Mr. Apr. My June July Aug. Sep. Oct. Nov. Dec. Triflurlin bql bql 4 bql bql 5 bql bql 6 bql Atrzine 1 bql bql DEA Dizinon 1 bql bql 2 bql bql bql bql Disulfoton 1 bql bql bql bql bql 3 bql bql 4 bql 0.05 bql bql bql 5 bql 0.03 bql bql 6 bql bql bql bql, below quntifiction limits. ously for the rpid, routine, unequivocl nd ccurte Klms River smples throughout the period from determintion of trce levels of pesticides in en- Jnury to December vironmentl wter smples. Contmintion by the detected pesticides showed The pesticides detected in river wter smples sptil vrition tht does not follow cler pttern. belong to different chemicl or/ nd ctive groups. Sesonl vritions of pesticide detection in Klms Six herbicides, EPTC, DEA, triflurlin, trzine, River wter smples, corresponding to pesticide terbuthylzine nd lchlor, nd seven insecticides, ppliction periods, were observed. Pesticide decrbofurn, dizinon, disulfoton, prthion methyl, tection tended to be more frequent nd levels more prthion ethyl, fenthion nd ethion, were detected in elevted during the lte Spring nd Summer months.

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