Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides

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If you believe that this item is subject to any of these criteria, or for any other reason should not be held on OpenAIR, then please contact openair-[email protected].uk with the details of the item and the nature of your complaint. GREEN PETRIE, B., MUÑOZ, M.D.C. and MARTIN, J. Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides. 2019 PETRIE, B., MUÑOZ, M.D.C. and MARTIN, J. 2019. Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides. Trends in analytical chemistry [online], 110, pages 249-258. Available from: https://doi.org/10.1016/j.trac.2018.11.010 PETRIE, B., MUÑOZ, M.D.C. and MARTIN, J. 2019. Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides. Trends in analytical chemistry, 110, pages 249-258. Held on OpenAIR [online]. Available from: https://openair.rgu.ac.uk/ AUTHOR ACCEPTED ELSEVIER Trends in analytical chemistry 0165-9936 BY-NC-ND 4.0 https://creativecommons.org/licenses/by-nc-nd/4.0 OpenAIR at RGU Digitally signed by OpenAIR at RGU Date: 2018.12.11 12:07:54 Z Accepted Manuscript Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides Bruce Petrie, Maria Dolores Camacho Muñoz, Julia Martín PII: S0165-9936(18)30537-5 DOI: https://doi.org/10.1016/j.trac.2018.11.010 Reference: TRAC 15312 To appear in: Trends in Analytical Chemistry Received Date: 9 October 2018 Revised Date: 6 November 2018 Accepted Date: 10 November 2018 Please cite this article as: B. Petrie, M.D. Camacho Muñoz, J. Martín, Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides, Trends in Analytical Chemistry, https:// doi.org/10.1016/j.trac.2018.11.010. This is a PDF file of an unedited manuscript that has been accepted for publication. 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MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 1 Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides 1 Bruce Petrie a *, Maria Dolores Camacho Muñoz b , Julia Martín c , 2 a School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK 3 b Laboratory for Lipidomics and Lipid Biology, Division of Pharmacy and Optometry, School of 4 Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester 5 Academic Health Science Centre, Manchester, M13 9PL, UK 6 c Department of Analytical Chemistry, Escuela Politécnica Superior, University of Seville, C/Virgen 7 de África, 7, 41011, Seville, Spain 8 * Corresponding author email: [email protected] Tel. +44 (0) 1224 262824 9 10 Abstract 11 Chiral pesticides can exert stereospecific toxicity in contaminated environmental compartments. 12 Therefore, measuring pesticides at the enantiomeric level is essential to assess the risk posed to 13 exposed organisms, including humans. In recent years, there has been rapid progress on the 14 development and application of stereoselective liquid chromatography-tandem mass spectrometry 15 (LC-MS/MS) methodologies for monitoring pesticides in the environment. Coupling chiral LC 16 separations with MS/MS detection enables trace enantiomeric determination of pesticides in complex 17 environmental matrices. The intent of this review is to provide an up-to-date synopsis on recent 18 advances of stereoselective LC-MS/MS methodologies for pesticide analysis. Key aspects of these 19 methodologies discussed include sample storage and extraction method, stationary phases for 20 separation, multi-residue separations, and method of quantitation. Finally, future trends in this rapidly 21 growing field of analytical chemistry research are outlined. 22 23 Key words: pesticide; chiral; enantiomer; LC-MS/MS; polysaccharide; environment; multi-residue; 24 fungicide; herbicide; insecticide 25 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 2 1. Introduction 26 Increasing pressure on food production has resulted in the continued development and use of 27 pesticides. Their persistence and mobility has seen them detected throughout the environment 28 including soils, sediments, plant matter, river water and ground water [1-7]. The potential negative 29 long-term health impacts to exposed organisms, including humans, remain largely unknown [8-10]. 30 Consequently, legislation is in place to control the use and exposure to pesticides. For example, the 31 European Union’s Drinking Water Directive stipulates a limit of 0.1 µg L -1 for individual pesticides in 32 water for human consumption. However, an important consideration for environmental pollutants 33 such as pesticides which is not currently addressed in legislation, is chirality. This is despite of a high 34 percentage of them being chiral (e.g., a compiled list of 1,693 pesticides identified 482 (28 %) as 35 chiral [11]). 36 Chiral compounds can exist in the form of enantiomers which have identical chemical structures but 37 different spatial arrangements around the stereogenic centre and are thus non-superimposable 38 stereoisomers (Figure 1). Enantiomers have identical physico-chemical properties, however they often 39 exhibit different pharmacokinetics and pharmacodynamics that can result in enantiomer dependent 40 toxicity [12-14]. For example, in vitro tests with Phythophthora infestans and Pythium ultimum found 41 the fungicide R-metalaxyl to be ~1,000 times more active that S-metalaxyl [15]. Toxicity testing has 42 found stereoselective toxicity for a number of pesticides including the insecticides profenofos and 43 fonofos towards Daphnia magna and Ceriodaphnia dubia [16]. The insecticide fipronil has also been 44 found to exhibit stereoselective toxicity towards C. dubia [17]. In this study S(+)-fipronil was found 45 to be 5 times more toxic than R(-)-fipronil during acute exposure. Despite enantiomers of chiral 46 pesticides differing in their toxicity, they are normally produced as a racemic mixture (i.e., equimolar 47 concentration of individual enantiomers) [18]. 48 Stereoselective degradation of chiral pesticides has been observed in soils, sediments, water and 49 plants [19-22], which can lead to the enrichment of the more or less toxic enantiomers. This process 50 can be driven biotically (e.g., by bacterial action) and abiotically (e.g., by chemical reaction). To 51 demonstrate, in anaerobic sediments S(+)-fipronil was preferentially degraded over R(-)-fipronil [23]. 52 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 3 A racemic enantiomeric fraction (0.55) was converted to 0.10-0.11 within 8 days. On the other hand, 53 S-metalaxyl (inactive enantiomer) was found to degrade faster than R-metaxyl in aerobic soil with pH 54 <4 and in anaerobic soils [24]. However, enrichment was found to proceed in either direction and was 55 dependent on the specific soil conditions. Furthermore, racemization is also possible whereby one 56 enantiomer is converted to another. For example, racemization of the fungicide triadimefon has been 57 observed in water [25] and in soil [26]. Li et al., [26] reported the conversion of S(+)-triadimefon to 58 R(-)-triadimefon in sterile soils, and was pH dependant. Nevertheless, enrichment (or racemization) 59 of enantiomers of varying toxicity in environment compartments requires their quantitation as 60 separate entities. 61 Gas chromatography (GC), liquid chromatography (LC) and capillary electrophoresis (CE) have all 62 previously been used to separate chiral pesticides at the enantiomeric level [23, 27, 28]. CE is the 63 least popular method for environmental analysis as it is not routinely coupled to mass spectrometry 64 (MS). In GC-MS and LC-MS methods, the most popular means of enantiomer separation is direct, 65 using chiral stationary phases. Here separation is reliant on the 3 point model whereby 3 points of 66 contact between the enantiomer and chiral stationary phase are needed to achieve chiral recognition 67 [29]. A review of ~500 pesticides by Alder et al. [27] concluded that LC-MS is superior to equivalent 68 GC-MS systems due to its wider scope of study and superior sensitivity. The shortcomings of GC-69 MS are its inability to analyze samples of low volatility, high polarity, or thermal instability. 70 Furthermore, the general trend of new pesticides on the market becoming more polar in nature makes 71 LC-MS the popular choice for analysis [30]. The improved specificity and sensitivity offered by 72 tandem mass spectrometers (MS/MS) such as triple quadrupole is essential for environmental 73 analysis. Therefore, the aim of this review is to appraise up-to-date stereoselective LC-MS/MS 74 methodologies for the determination of chiral pesticides in environmental samples. 75 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 4 2. Pesticide stability in collected samples 76 Sampling is a fundamental process in the determination of pollutants in the environment. It is 77 potentially the largest source of error yet it often receives little attention [31, 32]. An important 78 consideration during collection and storage of biologically active matrices such as environmental 79 samples is analyte stability [33, 34]. In particular, chiral analytes have the potential to undergo 80 stereoselective transformation during sampling and storage. 81 Stereoselective LC-MS/MS methodologies reported in the literature store liquid samples such as river 82 water prior to extraction and instrumental analysis at -20 ˚C (Table 1). Alternatively samples are 83 filtered (0.45 µm), adjusted to pH 1.5 and stored at 4 ˚C [35]. These approaches are adopted to 84 mitigate any potential stereospecific (and non-stereospecific) changes due to microbial activity. On 85 the other hand, care must be taken that the change to pH does not induce any abiotic processes which 86 cause pesticide loss or racemization. Similar to liquid samples, the common approach to store solid 87 samples prior to analysis is at temperatures of -20 ˚C or -40 ˚C (Table 1). Alternatively solid samples 88 have been air dried and stored in the dark at 4 ˚C or at room temperature [36]. However, air drying 89 samples (instead of lyophilizing) can increase the risk of sample contamination. Li et al. [37] 90 investigated the stability of the chiral insecticide flufiprole and flufiprole-amide in a variety of 91 matrices including rice, rice straw, water and soil stored at -20 ˚C. Samples were spiked at 92 environmentally relevant parts-per-billion (ppb) concentrations levels and analysed monthly. It was 93 found that no significant changes to the overall concentration or enantiomeric distribution were 94 observed for either analyte. 95 The potential influence of abiotic processes on stereoisomeric composition of chiral pesticides during 96 sample storage and processing also needs considered. Racemization of malathion, phenthoate and 97 fenpropathrin has been found in methanol, ethanol and water [25]. The extent of racemization was 98 affected by both temperature and pH, with this process proceeding more rapidly at neutral pH than pH 99 5.8. It was proposed that racemization occurred via proton exchange at the stereogenic centre [25]. 100 The synthetic pyrethroids cypermethrin and cyfluthrin have also been found to be unstable in sterile 101 water. Isomer conversion at the αC resulted in the stereoisomer converting to an epimer at rates of 102 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 5 0.050 and 0.044 day -1 , respectively [16]. On the other hand both cis-bifenthrin and permethrin were 103 stable. Such information is important to consider during sample storage and is often not investigated 104 (or reported) during development and validation of new methodologies (Table 1). 105 106 3. Extraction and clean-up methods 107 Several extraction and clean-up methods are utilized for chiral pesticides in environmental samples 108 prior to stereoselective LC-MS/MS (Table 1). Although extraction techniques should not be 109 stereoselective in nature, it is important they achieve adequate recovery (and reproducibility) of 110 pesticides from complex environmental matrices whilst reducing matrix interferences prior to 111 instrumental analysis. The most popular method of extraction and clean-up is the quick, easy, cheap, 112 effective, rugged and safe (QuEChERS) technique combined with (dispersive) solid phase extraction 113 (SPE) [38-43]. Such techniques are well established and have been discussed in detail elsewhere [44, 114 45]. Therefore, only the most up-to-date and alternative sample extraction methods are discussed 115 here. 116 Contemporary extraction methods in the literature report the use of microextraction techniques [35, 117 36, 46-48] (Table 1). Combining matrix solid phase dispersion (MSPD) and dispersive liquid-liquid 118 microextraction (DLLME) is proposed as a method to reduced matrix interferences and improve 119 sensitivity [49, 50]. Zhao et al. [48] optimized MSPD-DLLME for the determination of 8 chiral 120 pesticides (log K OW 1.7-4.3) in soil and sediment at the enantiomeric level. For MSPD 0.1 g of soil or 121 sediment was blended with 0.4 g of C18 sorbent and packed into an empty SPE cartridge. Analytes 122 were eluted in methanol and dried prior to the addition of 5 mL water ready for DLLME. 960 µL of 123 acetonitrile as the dispersing solvent and 550 µL dichloromethane as the extraction solvent was 124 injected rapidly into the aqueous sample [48]. Following 1.6 min sonication the homogenized 125 emulsion was centrifuged. The extraction solvent was removed and evaporated to dryness before 126 reconstitution in mobile phase and enantioselective LC-MS/MS analysis. Overall method recovery 127 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 6 ranged from 62-95 % for sediments and soils, with RSDs ≤10 % [48]. DDLME has also been 128 successfully applied for the extraction of six chiral pesticides in river water and wastewaters [46]. 129 Supramolecular solvents are proposed as an alternative means of extracting pesticides from 130 environmental samples. Supramolecular solvents are nano-structured water immiscible liquids 131 comprising three-dimensional amphiphilic aggregates [51]. They are suitable for the extraction of 132 polar analytes due to the polarity of the amphiphile head groups as well as the high concentration of 133 amphiphiles in the solvent (0.1-1 mg µL -1 ) [35]. Caballo et al. [36] adopted supramolecular solvent-134 based microextraction (SUSME) for the determination of mecoprop (log K OW 3.1) and dichlorprop 135 (log K OW 3.4) in water and soil. In this study, reverse aggregates of dodecanoic acid was used for 136 microextraction. Water was added to dodecanoic acid dissolved in tetrahydrofuran causing the 137 assembly of dodecanoic acid and formation of oily droplets (at pH <4) [35]. The proposed 138 mechanism of extraction into the supramolecular solvent is via hydrogen bonding and dispersion 139 interactions between the hydrophobic moieties of mecoprop and dichloroprop and the hydrocarbon 140 chain of dodecanoic acid. The less dense supramolecular extract (approximately 270 µL) was 141 removed, dried and 100 mM acetate buffer pH 5 added for back-extraction. The aqueous extract was 142 separated from insoluble matrix extracts and solid dodecanoic acid by centrifugation prior to LC-143 MS/MS analysis. Analyte recoveries using the SUSME technique was 73-80 % (RSDs ≤4 %) in 144 water samples and 66-83 % (RSDs ≤6 %) in soils samples [35, 36]. 145 An alternative sample extraction method based on the use of magnetic SPE utilizing multi-walled 146 carbon nanotubes (MWCNTs) has been reported by Zhao et al., [47]. MWCNTs represent an 147 emerging adsorbent comprising tubular graphite sheets. The incorporation of nanoparticles of 148 magnetic properties (e.g., Fe 3 O 4 ) into their structure enables easy phase separation, overcoming the 149 limitations of MWCNTs used in conventional SPE mode (e.g., blockages and loading time). In the 150 study by Zhao et al. [47], amino functionalized MWCNTs were synthesized to increase the 151 hydrophilicity of nanotubes which improves dispersion in water and analyte contact time. For the 152 analysis of water samples (200 mL), 75 mg of the synthesized composite was added and subject to 153 shaking at 150 rpm for 12 min for complete analyte adsorption. The MWCNTs were then separated 154 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 7 from the water using a magnet and dispersed in acetonitrile for analyte desorption. Acetonitrile was 155 evaporated to dryness and reconstituted in mobile phase ready for instrumental analysis. A total of 18 156 chiral pesticides including triazole fungicides, organophosphate insecticides, phenoxyalkanoic acid 157 herbicides, phenylpyrazole and neonicotinoid insecticides were successfully extracted. The studied 158 pesticides encompassed a range of chemical properties. For example, dinotefuran is considered 159 hydrophilic with a log K OW -0.6 whereas profenofos is comparatively hydrophobic with a log K OW 4.7. 160 The optimized protocol achieved analyte recoveries in the range 80-106 % (RSDs ≤13 %) for a 161 variety of environmental matrices including river waters, wastewaters, soils and sediments. 162 163 4. Stereoselective LC-MS/MS methods 164 4.1. Polysaccharide stationary phases 165 Reported stereoselective LC-MS/MS methods all adopt chiral stationary phases to achieve direct 166 enantioseparations (Table 1). Among commercially available chiral stationary phases, polysaccharide 167 phases are popular due to their high selectivity, sensitivity and reproducibility [39, 42, 52], and it is 168 reported that 95 % of chiral compounds have been resolved by polysaccharide phases [53]. These 169 macromolecular chiral selectors are either amylose or cellulose based. However, cellulose and 170 amylose in their native state results in poor resolution and peak broadening due to slow diffusion of 171 analytes through the polymer network [39]. To overcome this shortcoming, derivatives of amylose 172 and cellulose were synthesized. This involves the reaction of hydroxyl functional groups with 173 appropriate reagents to produce derivative forms such as cellulose or amylose tris-(3,5-174 dimethylphenylcarbamate) (Figure 2). Such derivatives have a high number of chiral centres in the 175 ordered polysaccharide backbone, as well as the phenyl ring and carbamate groups providing sites for 176 π-π and hydrogen bonding interactions. Both the backbone structure and derivative group influence 177 enantioseparations. To demonstrate, Pan et al. [42] compared cellulose and amylose with the same 178 derivative in their structure (tris-(3,5-dimethylphenylcarbamate)) for the separation of the fungicide 179 zoxamide. The amylose based stationary phase provided superior resolving ability over cellulose for 180 this pesticide. On the other hand, different chiral recognition was observed between two amylose 181 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 14 References 341 [1] L. Hu, G. Zhang, B. Zheng, Y. Qin, T. Lin, Z. Guo, Chemosphere 77 (2009) 663. 342 [2] Y.F. Jiang, X.T. Wang, Y. Jia, F. Wang, M.H. Wu, G.Y. Sheng, J.M. Fu, Journal of 343 Hazardous Materials 170 (2009) 989. 344 [3] S.J. Lehotay, K.A. Son, H. 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Derivatives of cellulose and amylose chiral selectors previously used for the separation of 469 pesticide enantiomers 470 O OR RO OR O n Cellulose O R= 4-methylbenzoate 3,5-dimethylphenylcarbamate 3,5-dichlorophenylcarbamate 4-chloro-3methylphenylcarbamate 5-chloro-2-methylphenylcarbamate 3-chloro-5methylphenylcarbamate Amylose 3,5-dimethylphenylcarbamate π-acceptor H-bonds π-acceptor H-bonds MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 19 471 Figure 3. Multi-residue stereoselective LC-MS/MS chromatograms of chiral pesticides separated 472 using immobilized amylose tris-(3-chloro-5-methylphenylcarbamate) (250 x 4.6 mm, internal 473 diameter 5 µm) maintained at 30 °C with a mobile phase consisting 5 mM ammonium acetate + 0.05 474 % formic acid : acetonitrile 47:53 at 0.6 mL min -1 (reproduced with permission, [47]). 475 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 20 Table 1. Stereoselective LC-MS/MS methodologies for chiral pesticides in environmental matrices 476 Group Target(s) Matrix Sample collection and storage Extraction & clean up Stationary phase & column dimensions Mobile phase conditions and run time Ionization source & detector Calibration method R S Signal suppression (%) Recovery (%) LOD (ppb) Ref. Fungicides, insecticides & herbicides Metalaxyl, epoxiconazole, myclobutanil, hexaconazole, napropamide & isocarbophos River water (200mL), wastewater (200mL) Stored in amber bottles @ -20 °C. Filtered (0.45 µm) SPE + DLLME Cellulose tris-(3,5- dimethylphenylcarbamate) 150 x 4.6 mm i.d., 5 µm 0.1 % FA: ACN (60:40 v/v) @ 0.6 mL/min. 30 °C. 10 µL injection. 70 min. ESI+ MS/MS Matrix matched ≥1.5 -49 to -3 83-103 0.1-0.5 [46] Fungicides, insecticides & herbicides Triadimenol, hexaconazole, metalaxyl, napropamide, isocarbophos, epoxiconazole, paclobutrazol, diniconazole, triazolone, fenamiphos, imazalil, difenoconazole, fenbuconazole, profenofos, fipronil, tebuconazole, dinotefuran & propiconazole Soil (2g), sediment (2g), river water (200mL), wastewater (200mL) Dried @ 35 °C, sieved (154 µm) & stored @ - 20 °C in the dark. SLE + MSPE (m- MWCNTs- NH 2 ) Amylose tris-(3-chloro- 5methylphenylcarbamate) 250 x 4.6 mm i.d., 5 µm ACN: 5 mM NH 4 OAc + 0.05% FA (53:47 v:v) @ 0.6 mL/min. 55 min. ESI+/- MS/MS Matrix matched ≥1.5 -50 to 33 81-106 0.1-0.6 [47] Fungicides, insecticides & herbicides Myclobutanil, hexaconazole, metalaxyl, napropamide, isocarbophos, epoxiconazole, paclobutrazol & diniconazole Soil (0.1g), sediment (0.1g) Air dried, sieved (154 µm) & stored @ -20 °C in the dark. MSPDDLLME Cellulose tris-(3,5- dimethylphenylcarbamate) 150 x 4.6 mm i.d., 5 µm 0.1 % FA: ACN (60:40 v/v) @ 0.6 mL/min. 30 °C. 10 µL injection. 70 min. ESI+ MS/MS Matrix matched + Internal standard (deuterated surrogates) ≥1.5 -33 to 4 62-95 0.2-1.5 [48] Fungicides Benalaxyl & benalaxyl acid Soil (10g) Samples collected from laboratory study & stored @ -20 °C SLE Cellulose tris-(3,5- dichlorophenylcarbamate) 250 x 4.6 mm i.d. ACN:H 2 O:FA (90:10:0.1, v/v/v) @ 0.5 mL/min. 20°C. 10 min. ESI+ MS/MS Matrix matched NR NR 81-104 1.5-5.6 [52] Fungicides Zoxamide Soil, fruits & vegetables (10g), water (10mL) Samples collected from laboratory study and stored @ -20 °C QuEChERS & dSPE Amylose tris-(5-chloro-2- methylphenylcarbamate) 150 × 2 mm i.d., 3 µm ACN: H 2 O (70:30 v/v) @ 0.5 mL/min. 25 °C. 2 µL injection. 3.5 min. ESI+ MS/MS Matrix matched >1.5 0 to 121 90-117 0.5* [42] Insecticides Flufiprole & flufiproleamide 10g (vegetables), 5g (soil) Samples collected from field study and stored @ -20 °C. Stability in solvent & matrix matched standards QuEChERS & SPE Cellulose tris-(4-chloro-3- methylphenylcarbamate) 150 × 2.0 mm i.d., 3 µm ACN:0.1 % FA (65:35 v/v) @ 0.25 mL/min. 25 °C. 1 µL injection. 7 min. ESI+ MS/MS Matrix matched ≥2.7 -19 to 17 84-107 <2 [37] MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 21 assessed @ -20 °C Fungicides Pyrisoxazole 10g (vegetables & fruit), 5g (soil) 2 kg strawberries from 8 randomly selected sites, homogenized & stored @ -20 °C QuEChERS & dSPE Cellulose tris-(4- methylbenzoate) 150 × 2.0 mm i.d., 3 µm MeOH: H 2 O (70:30 v/v) @ 0.35 mL/min. 30 °C. 10 min. ESI+ TOF/MS Matrix matched ≥2.4 -51 to 108 64-100 0.2-1 [41] Fungicides Metalaxyl, myclobutanil, paclobutrazol, diniconazole, hexaconazole, triadimefon, epoxiconazole, tetraconazole, famoxadone, & fenbuconazole Fruit and vegetables (10g) 135 (various) samples collected from several markets QuEChERS & dSPE Cellulose tris-(3,5- dimethylphenylcarbamate) 150 × 2.0 mm i.d., 3 µm 2 mM NH 4 OAc:ACN gradient @ 25 °C. 5 µL injection. 25 min. ESI+ MS/LIT Matrix matched >1.5 -35 to 138 70-120 0.05- 1* [40] Insecticides Isocarbophos & isocarbophos oxon Soil and rice (5g), water (100mL) Samples collected from laboratory study & stored @ -20 °C QuEChERS & SPE Amylose tris-(3,5- dimethylphenylcarbamate) 150 × 2 mm i.d., 3 µm ACN with 0.1 % FA: 0.1% FA solution @ 0.3 mL/min. 5 µL injection. 11 min. ESI+ MS/MS Matrix matched NR -13 to 6 90-103 0.1-0.5 [58] Herbicides Mecoprop & dichlorprop Soil (0.8g) Air dried , sieved (2mm) & stored @ 4 °C in the dark SUSME α-CD permethylated 200 × 4 mm i.d., 5 µm MeOH:100 mM FA/NH 4 HCO 2 (pH 4.0) (65:35 v/v) @ 0.5 mL/min. 25 °C. 40 µL injection. 13 min. ESIMS/MS Internal standard (deuterated surrogates) NR NR 66-83 0.03 [36] Fungicides & insecticides Cisepoxiconazole & indoxacarb Soil (5g), teas (2g), infusion (3g) 15 random samples collected from field study, sieved & stored @ -18 °C USE & SPE Cellulose tris (3,5- dimethylphenylcarbamate) 150 × 2 mm i.d., 3 µm 0.2% TFA and 2 mM NH 4 HCO 2 aqueous solution: MeOH (25:75 v/v) @ 0.4 mL/min. 40 °C. 20 min. ESI+ QTOF/MS Matrix matched NR -71 to 100 61-130 <1.4 [57] Herbicides Mecoprop & dichlorprop River & ground water Grab samples in dark glass containers, filtered (0.45 µm), adjusted to pH 1.5 & stored @ 4 °C. SUSME α-CD permethylated 200 × 4 mm i.d., 5 µm MeOH:100 mM FA/ NH 4 HCO 2 (pH 4.0) (65:35 v/v) @ 0.5 mL/min. 25 °C. 40 µL injection. 13 min. ESIMS/MS Internal standard (deuterated surrogates) ≥1.9 NR 73-80 0.001- 0.004 [35] Herbicides, insecticides & fungicides Indoxacarb, benalaxyl, carfentrazoneethyl, quizalofopethyl, isocarbophos, fenamiphos, simeconazole, napropamide & paclobutrazol Soil (10g) & river water (100mL) 15 random soil samples collected from field study @ varying depths (0-30 cm), air dried, sieved (2 mm) & stored in the dark. Grab samples of river water collected. QuEChERS & dSPE/SPE Amylose tris-(3,5- dimethylphenylcarbamate) 150 × 4.6 mm i.d., 5 µm ACN:2 mM NH 4 OAc in water (gradient) @ 0.45 mL/min. 25 °C. 10 µL injection. 35 min. ESI+ MS/MS Matrix matched ≥1.5 -10 to 19 78-106 <1.8 [39] Fungicides Myclobutanil Cucumber and soil (10g) 15 random samples collected from greenhouse study @ QuEChERS & SPE Cellulose tris-(3,5- dimethylphenylcarbamate) 150 × 4.6 mm i.d., 5 µm ACN:H 2 O (70:30 v/v) @ 0.5 mL/min. 40 °C. 10 µL injection. 10 min. ESI+ MS/MS Matrix matched NR -32 to 55 >50 0.6-1.0 [56] MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT 22 varying time intervals (0-15 cm depths for soils). Fungicides Tetraconazole, fenbuconazole, epoxiconazole, diniconazole, hexaconazole, triadimefon, paclobutrazol, & myclobutanil Soil (10g) & water (100mL) Samples collected from field study & stored in the dark @ -20 °C. QuEChERS & dSPE/SPE Cellulose tris-(3,5- dimethylphenylcarbamate) 150 × 4.6 mm i.d., 5 µm ACN:2 mM NH 4 OAc in water (55:45 v/v) @ 0.45 mL/min. 25 °C. 10 µL injection. 25 min. ESI+ MS/MS Matrix matched ≥1.5 2 to 10 76–108 (soil), 81–107 (water) <1 [38] Fungicides Epoxiconazole Grape & soil (10g) Samples collected from field study @ different time intervals. 2 kg of grape & 8 random soil sampling points collected. Stored @ -20 °C. USE & SPE Cellulose tris (3,5- dimethylphenylcarbamate) 150 x 2.0 mm, i.d., 3 µm ACN:H 2 O (90:10 v/v) @ 0.3 mL/min. 10 µL injection. 5 min. ESI+ MS/MS Matrix matched NR 69 to 89 76-92 5 [55] Fungicides Benalaxyl, furalaxyl & metalaxyl Vegetables & fruits (15g) - QuEChERS & dSPE Cellulose tris-(4-chloro-3- methylphenylcarbamate) 150 x 2 mm i.d., 3 µm ACN:0.1 % FA solution (45:55 v/v) @ 0.2 mL/min. 5 µL injection. 25 min. ESI+ MS/MS Matrix matched ≥1.7 -10 to 10 81-96 0.3 [43] Insecticides Isocarbophos Soil (5g) Samples collected from laboratory study @ different time intervals & stored @ -40 °C QuEChERS Amylose tris-(3,5- dimethylphenylcarbamate) 150 x 2.1 mm i.d., 3 µm ACN:2 mM NH 4 OAc solution + 0.1 % formic acid (60:40 v/v) @ 0.3 mL/min. 10 µL injection. 5 min. ESI+ MS/MS Matrix matched NR 10 to 18 89-97 5 [59] Key: ACN, Acetonitrile; CD, Cyclodextrin; FA, formic acid; LOD, limit of detection; *LOQ, limit of quantification; MeOH: methanol; MS/MS, tandem mass 477 spectrometry; MSPD, matrix solid phase dispersion; NH 4 HCO 2 ; ammonium formate; NH 4 OAc, ammonium acetate; QuEChERS, quick, easy, cheap, 478 effective, rugged and safe method; SPE, solid phase extraction; dSPE, dispersive solid phase extraction; MSPE, magnetic solid phase extraction; m-479 MWCNTs-NH 2, magnetic amino modified multiwalled carbon nanotubes; SLE, solid liquid extraction; SUSME, supramolecular solvent-based 480 microextraction; DLLME, dispersive liquid-liquid microextraction; TFA: trifluoroacetic acid; TOF/MS, time-of-flight mass spectrometer; USE, ultrasonic 481 solvent extraction; NR, not reported; ESI, electrospray ionization; R S , resolution 482 483 MANUS CRIP T ACCEP TED ACCEPTED MANUSCRIPT • Progress on development of stereoselective LC-MS/MS pesticide methods reviewed • Possible enantiomer changes by (a)biotic processes during sample storage overlooked • Polysaccharide derivative phases offer wide scope for pesticide separations • Stereoselective LC-MS/MS methods for multi-residue analysis now being developed • Lack of deuterated surrogates and metabolites available for monitoring studies