Microwave assisted solvent extraction and coupled-column reversed-phase liquid chromatography with UV detection use of an analytical restricted-access-medium column for the efficient multi-residue analysis of acidic pesticides in soils.

A screening method has been developed for the determination of acidic pesticides in various types of soils. Methodology is based on the use of microwave assisted solvent extraction (MASE) for fast and efficient extraction of the analytes from the soils and coupled-column reversed-phase liquid chromatography (LC-LC) with UV detection at 228 nm for the instrumental analysis of uncleaned extracts. Four types of soils, including sand, clay and peat, with a range in organic matter content of 0.3-13% and ten acidic pesticides of different chemical families (bentazone, bromoxynil, metsulfuron-methyl, 2,4-D, MCPA, MCPP, 2,4-DP, 2,4,5-T, 2,4-DB and MCPB) were selected as matrices and analytes, respectively. The method developed included the selection of suitable MASE and LC-LC conditions. The latter consisted of the selection of a 5-microm GFF-II internal surface reversed-phase (ISRP, Pinkerton) analytical column (50 x 4.6 mm, I.D.) as the first column in the RAM-C18 configuration in combination with an optimised linear gradient elution including on-line cleanup of sample extracts and reconditioning of the columns. The method was validated with the analysis of freshly spiked samples and samples with aged residues (120 days). The four types of soils were spiked with the ten acidic pesticides at levels between 20 and 200 microg/kg. Weighted regression of the recovery data showed for most analyte-matrix combinations, including freshly spiked samples and aged residues, that the method provides overall recoveries between 60 and 90% with relative standard deviations of the intra-laboratory reproducibility's between 5 and 25%; LODs were obtained between 5 and 50 microg/kg. Evaluation of the data set with principal component analysis revealed that the parameters (i) increase of organic matter content of the soil samples and (ii) aged residues negatively effect the recovery of the analytes.     

Determination of metribuzin and major conversion products in soils by microwave-assisted water extraction followed by liquid chromatographic analysis of extracts

A multiresidue method developed for the analysis of metribuzin and its major conversion products, deaminometribuzin (DA), diketometribuzin (DK) and deaminodiketometribuzin (DADK), in soils is presented. The method is based on microwave-assisted water extraction (MAWE) of soils using 10 mM phosphate buffer, pH 7 as extractant and analysis of aqueous extracts by HPLC-diode array detection. MAWE operational parameters were optimized with respect to extraction efficiency of the target compounds from soils with 1.5 and 3.5% organic matter content. Recoveries of all solutes above 80% were obtained from soils with 1.5% organic matter content; respective LOD and LOQ levels were determined at 5 and 10 micrograms/kg. In soils with organic matter content 3.5%, recoveries of all solutes were lower (< 70%) and the respective LOD and LOQ values were determined at 10 and 50 micrograms/kg. However, recoveries of fresh and aged residues, the latter weathered under cold storage conditions, were not statistically different for both types of soils.     

Determination of linuron and related compounds in soil by microwave-assisted solvent extraction and reversed-phase liquid chromatography with UV detection

The combination of microwave-assisted solvent extraction (MASE) and reversed-phase liquid chromatography (RPLC) with UV detection has been investigated for the efficient determination of phenylurea herbicides in soils involving the single-residue method (SRM) approach (linuron) and the multi-residue method (MRM) approach (monuron, monolinuron, isoproturon, metobromuron, diuron and linuron). Critical parameters of MASE, viz, extraction temperature, water content and extraction solvent were varied in order to optimise recoveries of the analytes while simultaneously minimising co-extraction of soil interferences. The optimised extraction procedure was applied to different types of soil with an organic carbon content of 0.4-16.7%. Besides freshly spiked soil samples, method validation included the analysis of samples with aged residues. A comparative study between the applicability of RPLC-UV without and with the use of column switching for the processing of uncleaned extracts, was carried out. For some of the tested analyte/matrix combinations the one-column approach (LC mode) is feasible. In comparison to LC, coupled-column LC (LC-LC mode) provides high selectivity in single-residue analysis (linuron) and, although less pronounced in multi-residue analysis (all six phenylurea herbicides), the clean-up performance of LC-LC improves both time of analysis and sample throughput. In the MRM approach the developed procedure involving MASE and LC-LC-UV provided acceptable recoveries (range, 80-120%) and RSDs (<12%) at levels of 10 microg/kg (n=9) and 50 microg/kg (n=7), respectively, for most analyte/matrix combinations. Recoveries from aged residue samples spiked at a level of 100 microg/kg (n=7) ranged, depending of the analyte/soil type combination, from 41-113% with RSDs ranging from 1-35%. In the SRM approach the developed LC-LC procedure was applied for the determination of linuron in 28 sandy soil samples collected in a field study. Linuron could be determined in soil with a limit of quantitation of 10 microg/kg.     

Analysis of polycyclic aromatic hydrocarbons in water and beverages using membrane-assisted solvent extraction in combination with large volume injection-gas chromatography-mass spectrometric detection

Membrane-assisted solvent extraction (MASE) in combination with large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS) was applied for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) in aqueous samples. The MASE conditions were optimized for achieving high enrichment of the analytes from aqueous samples, in terms of extraction conditions (shaking speed, extraction temperature and time), extraction solvent and composition (ionic strength, sample pH and presence of organic solvent). Parameters like linearity and reproducibility of the procedure were determined. The extraction efficiency was above 65% for all the analytes and the relative standard deviation (RSD) for five consecutive extractions ranged from 6 to 18%. At optimized conditions detection limits at the ng/L level were achieved. The effectiveness of the method was tested by analyzing real samples, such as river water, apple juice, red wine and milk.     

Matrix Solid Phase Dispersion‐Accelerated Solvent Extraction for Determination of OCP Residues in Fish Muscles

A rapid, sensitive and accurate matrix solid phase dispersion‐accelerated solvent extraction (MSPD‐ASE) method for selective determination of sixteen organochlorine pesticide (OCP) residues in fish samples has been developed and validated. 2 g fresh fish muscle was dispersed with 10 g anhydrous sodium sulfate and 2 g acid alumina thoroughly, and loaded into the stainless‐steel extraction cell containing 6 g of acid alumina and 10 g anhydrous sodium sulfate. The temperature 60 °C and two extraction cycles of 5 min gave adequate extraction efficiency using DCM‐hexane (3:7, v/v) mixture as solvent. Not only the lipids, but also other co‐extracts, which peaks mostly located in the forepart of chromatograms and maybe interfere the identification or quantitation of analytes, were eliminated exhaustively, while analytes were extracted selectively. Sixteen OCPs were identified by retention time of standards and quantified using mirex as internal standards. These detected OCPs were confirmed by GC‐MS in real samples. The performance of proposed method was evaluated and validated: the detection limits were 0.008‐0.05 ng g^‐1, relative standard deviations were 1.9‐5.0%, and recoveries were 91.0‐104.1% spiked at 10 ng g^‐1 level. The accuracy and precision of proposed method were equal to or better than that of traditional Soxhlet extraction method.     

LC–UV determination of atrazine and its principal conversion products in soil after combined microwave-assisted and solid-phase extraction

A multiresidue method developed for the analysis of atrazine and its principal conversion products, deisopropylatrazine (DIA), deethylatrazine (DEA) and hydroxyatrazine (HA), in soil is presented. The method is based on the microwave-assisted extraction (MAE) of soil with aqueous methanol followed by solid-phase extraction (SPE) of the extracts and subsequent analysis by LC–UV with a diode array detector. MAE operational parameters (extraction solvent, extractant volume) were optimized with respect to extraction efficiency of the target compounds from soils with 2.5% organic matter (OM) content. Recoveries above 80% were obtained for all solutes. Soil OM content did not affect analyte recoveries. Recoveries from fresh and aged residues, the latter weathered under cold storage conditions, were not statistically different. Finally, MAE was found to be superior in terms of extraction efficiency, sample throughput, and solvent consumption to conventional flask-shaking extraction.     

加速溶剂萃取-磁固相萃取净化-气相色谱-质谱法测定土壤中16种多环芳烃和23种有机氯残留

建立了加速溶剂萃取（ASE）、磁固相萃取净化（MSPE）、气相色谱-质谱（GC-MS）测定土壤中多环芳烃和有机氯残留的方法。ASE萃取溶剂为丙酮-正己烷（1：1，v/v），萃取温度为100℃，萃取压力为11.032 MPa，加热时间为5 min，静态萃取时间为5 min，循环萃取3次，冲洗体积为60%萃取池体积，氮气吹扫100 s。然后采用室温制备法自制ZIF-8/nZVI磁性材料用于净化萃取液，将净化液浓缩定容后进行GC-MS测定。多环芳烃和有机氯的线性范围为5~200 μg/kg，线性相关系数（r²）均大于0.99；目标物的检出限（LOD，S/N=3）为0.04~1.21 μg/kg。所建方法成功用于土壤样品中16种多环芳烃和23种有机氯的测定，在3个加标水平下得到的加标回收率为63.9%~112.1%，相对标准偏差（RSD）为0.4%~26.2%。研究结果表明，该方法具有灵敏度高、重现性好、回收率高等特点，适用于土壤中多环芳烃和有机氯残留的检测。     

Effect of organic matter content in the trace analysis of triazines in various types of soils with GC-NPD

Summary Recent work demonstrated that the combination of microwave assisted solvent extraction (MASE) and capillary gas chromatography with selective nitrogen detection (GC-NPD) is a viable approach for the efficient determination of triazine herbicides in soils. However, for soils with a high organic matter content or the injection of more concentrated extracts to obtain lower LOD's the performance of gas chromatographic analysis of uncleaned extracts is hampered. This results in both a decrease of the chromatographic response of analytes and a decrease in the life time of the column due to coextracted matrix substances. The effect of various types of soils on the chromatographic analysis of triazine herbicides was studied. It appeared that for the investigated samples with an organic matter content below 5% processing of uncleaned extracts is possible. Samples with a higher organic matter content required a cleanup step. A rapid procedure on 100 mg silica cartridges has been developed using solvents compatible with the MASE extracts and the instrumental analysis. Beside the testing with different standard soils, about 120 samples of an ongoing monitoring program involving three different types of soil (organic matter content: 3–37%) were analysed. The selected compounds atrazine, desethylatrazine, desisopropyl-atrazine and simazine could be assayed in the various soil types to a level of at least 2 μg kg⁻¹. For soil samples with a high organic matter content (>5%), the rapid cleanup procedure allowed the trace analysis of the triazines and considerably increased the life time of the capillary column. Recoveries at levels from 2 to 50 μg kg⁻¹ ranged from 70 to 100% with RSDs ranging from 5.1 to 9.5%. Confirmation of positive samples was carried out by gas chromatography mass spectrometry.     

Continuous ultrasound-assisted extraction coupled to on line filtration-solid-phase extraction-column liquid chromatography--post column derivatisation-fluorescence detection for the determination of N-methylcarbamates in soil and food

A dynamic ultrasound-assisted method for the extraction of N-methylcarbamates (oxamyl, dioxacarb, metolcarb, carbofuran, carbaryl and isoprocarb) from soils and foods is proposed. The main factors affecting the extraction efficiency have been optimised by means of a central composite design. Pure water can be used as leaching agent. A flow injection manifold coupled to the extractor allows automation of the several steps involved in the analytical process. The method allows extraction of the carbamates from soil and food at 1 microg/g spiked level, with recoveries similar to those provided by the EPA 8318 method, without degradation of the target compounds during the extraction and with drastic shortening of the time required for this step (2 min vs. 4 h). Recoveries of the target analytes were 77-95% for spiked soil and 85-101% for spiked food. The detection and quantification limits were 12 and 40 ng/g, respectively, for all analytes, except carbaryl (detection and quantification limits 3 and 10 ng/ng, respectively). The relative standard deviations for repeatability and within-laboratory reproducibility were 3.1 and 7.5%, respectively.     

Optimisation of pressurised liquid extraction for the ultra-trace quantification of 20 priority substances from the European Water Framework Directive in atmospheric particles by GC-MS and LC-FLD-MS/MS

Atmospheric deposition plays an important role in environmental pollution and human health. However, very few information is available on the presence, in atmospheric particles, of organic priority substances in contrast to inorganic fraction. A method for the extraction and quantification of 20 priority organic substances listed in the European Water Framework Directive in atmospheric particles was developed. This method consists in a combination of gas chromatography coupled with mass spectrometry and ultra-high-pressure liquid chromatography coupled with tandem mass spectrometry and fluorescence. Optimized pressurized liquid extraction using a hexane/dichloromethane/isopropanol mixture was used as extraction procedure from atmospheric particulate matter. The influence of several extraction experimental factors related to the PLE was investigated. The optimized extraction method (80°C, 40 bar, 10 min, 1 cycle) exhibited average recoveries of target analytes higher than 62%. The method detection limits (MDL) were between 0.3 ng g(-1) and 83 ng g(-1). This extraction method, combined with sensitive analytical techniques, leads to satisfactory reliability, sensitivity, and accuracy. The method was applied to real samples, collected from two urban sites by an atmospheric sampling prototype developed in this study. The first results reveal a systematic presence of PAHs at high levels (ranging from 500 ng g(-1) to 10 μg g(-1)) and a variable and lower presence of pesticides at concentrations below 50 ng g(-1) in the samples.     

Determination of the fungicides vinclozolin and dicloran in soils using ultrasonic extraction coupled with solid-phase microextraction

Solid-phase microextraction (SPME) coupled to ultrasonic extraction was evaluated for extracting trace amounts of two agrochemical fungicides, vinclozolin and dicloran, in soil samples. Extraction was performed following two experimental approaches prior to the submission of the aqueous extracts to SPME-GC analysis. In the first approach, extraction involved sample homogenization with a water solution containing 5% (v/v) acetone and centrifugation prior to fiber extraction. In the second approach, the extraction of the fungicides from the soil samples was conducted using acetone as organic solvent which was then diluted with water to give a 5% (v/v) content. The pesticides were isolated with fused silica fiber coating with 85 μm polyacrylate. Parameters that affect both the extraction of the fungicides by the soil samples and the trapping of the analytes by the fiber were investigated and their impact on the SPME-GC-MS was studied. The procedures with respect to repeatability and limits of detection were evaluated by soil spiked with both analytes. Repeatability was between 5.6 and 14.2% and the limits of detection were 2-13 ng g⁻¹. The efficiency of acetone/SPME was generally better than that for water/SPME procedure showing good linearity (R²>0.99) with coefficient variations below 9%, recoveries higher than 91% and limits of detection between 2 and 3 ng g⁻¹. Finally, the recoveries obtained with acetone/SPME procedure were compared with the conventional liquid-liquid extraction using real soil samples. The acetone/SPME method was shown to be an inexpensive, fast and simple preparation method for the determination of target analytes at low nanogram per gram levels in soils.     

Determination of three anabolic compounds in calf urine by liquid chromatography with photodiode-array detection

A method for the determination of three anabolic hormones (diethylstilbestrol, dienestrol and trenbolone) in calf urine is described. After enzymatic hydrolysis, the samples were cleaned up by C18 solid-phase extraction. Drugs were extracted with hexane and analyzed by isocratic elution on a Discovery RP-Amide C16 5 microns column with photodiode-array detection at 240 and 347 nm. Both retention time and UV spectra were used for identification. Detection limits for the HPLC system were calculated to be 0.3 ng injected for all analytes in the standard mixture. However, for urine samples these limits increased because of the presence of unidentified matrix components. After extraction from urine, the limits of detection for the whole analytical procedure were 5 and 10 ng injected for trenbolone and stilbenes, respectively. The average recoveries of the hormones from spiked samples were in the range 53.1-56.7% with RSD between 11.3 and 14.5% for the whole procedure in the concentration range 25-2.5 ng ml-1.     

Microwave-assisted solvent extraction of the herbicide methabenzthiazuron from soils and some soil natural organic and inorganic constituents. Influence of environmental factors on its extractability

A microwave-assisted solvent extraction (MASE) method for the determination of methabenzthiazuron (MBT) in soil samples by HPLC-DAD (diode array detection) was evaluated. Spiked soil samples having different physico-chemical properties, and selected soil-derived matrices with diverse MBT adsorption capacity, characterized by their Freundlich equation Kf values, were used to verify the method applicability to a broad range of different soils. The spiking procedure was considered a crucial point to reproduce as closely as possible the solute-soil adsorption taking place in the natural environment. Ageing effects, where the compound could diffuse into inaccessible locations within the soil matrix in view of its great stability, were considered of particular concern. In spite of the heterogeneous physico-chemical properties of soils under study, recoveries were greater than 90%. Performance of the MASE procedure correlated highly with the adsorption capacity of soil-derived matrices: the lowest recoveries were for illite (67-73%), among the mineral surfaces, and for a humic acid (67-72%), among the organic fractions. Intra-assay variation for each type of sample soil range from 0.40 to 3.89%(RSD). Limits of detection and quantification were 0.047 and 0.15 microg g(-1), respectively. Analyte residence time was not a very significant factor on the extractability.     

Influence of the soil matrices on the analytical performance of headspace solid-phase microextraction for organotin analysis by gas chromatography-pulsed flame photometric detection

Organotin compounds (OTCs) have been identified in a variety of environmental media (air, surface water, groundwater, soil and sediments). In the past, much attention was assigned to the study of the OTCs content in biological samples, water and sediments. Little information about OTCs in soil is available. In this work, a procedure for butyl and phenyltin determination in soils by headspace-solid-phase microextraction (HS-SPME) gas chromatography-pulsed flame photometric detection (GC-PFPD) was investigated. For SPME analysis, a polydimethylsiloxane (PDMS) coating was applied. Peat soil rich in organic matter and with a high cation-exchange capacity (CEC), and clay soil low in organic matter and with a low CEC were analysed. The influence of these different soil matrices on HS-SPME analysis was evaluated by spiking of samples. In general, the recoveries for the two spiked soils exceeded 80%. The repeatability of the method was better than 10%. The limits of detection (LODs) and limits of quantification (LOQs) were in the ng S ng(-1) range. The technique may be reliably applied for the determination of butyltins and monophenyltin in soils, while it shows some limitations for the analysis of di- and triphenyltin (TPhT).     

Analysis of estrogens in river sediments by liquid chromatography-electrospray ionisation mass spectrometry. Comparison of tandem mass spectrometry and time-of-flight mass spectrometry

A method has been developed and optimised for the determination of two natural estrogens, estrone (E1) and 17beta-estradiol (E2), and one synthetic estrogen, 17alpha-ethynylestradiol (EE2), in river sediments at the sub-ng/g level. This procedure includes microwave-assisted solvent extraction (MASE), solid-phase extraction and high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionisation. Using sediments spiked with the three estrogens at 10 ng/g wet weight, efficient extraction (>92%) of all the three analytes was achieved by MASE, and whole-procedure recoveries ranged from 82 to 98%. Optimisation of the LC separation allowed for substantial reduction of ionisation suppression in the electrospray source to a final level of <18% suppression. Time-of-flight mass spectrometry (TOF-MS) and MS/MS were compared for the analysis of sediment extracts, with the latter technique proving to be the most selective. The method detection limits achieved by LC-MS/MS were 15, 30 and 40 pg/g for E1, E2 and EE2, respectively, which were 13-fold lower than those obtained by LC-TOF-MS. Analysis of river sediments collected from the River Ouse, UK, showed the presence of the natural estrogens at sub-ng/g level. E1 levels ranged from 0.40 ng/g (dry weight) to 3.30 ng/g while E2 levels ranged from <0.03 to 1.20 ng/g and EE2 was never detected (<0.04 ng/g).     

Microwave-assisted micro-solid-phase extraction for analysis of tetracycline antibiotics in environmental samples

In this study, a novel solid-liquid-solid extraction approach, which was termed ‘microwave-assisted micro-solid-phase extraction’ (MAE-μ-SPE), was developed. Target analytes were extracted from the sample into extraction solvent enhanced by microwave field, following adsorption by the adsorbent in the micro-solid-phase extraction device. Without any clean-up steps, the extracts were analysed by high performance liquid chromatography coupled with ultra-violet detector. The MAE-μ-SPE approach was developed for the extraction of four tetracycline antibiotics residues in environmental soil, sludge and atmospheric particulate matters. Variables affecting extraction procedures were systematically investigated. Low detection limits of 0.1–6.3 ng/g and low quantification limits of 0.33–20.7 ng/g were achieved under optimised conditions. The recoveries of antibiotics ranged from 70.6% to 110.5% with relative standard deviation of less than 15.1%. The predominance was showed when compared to conventional MAE and μ-SPE method. According to the results, MAE-μ-SPE was proved to be a simple and effective sample preparation method for the analysis of trace organic contaminants in environmental samples.     

Assay of TNP-470 and its two major metabolites in human plasma by high-performance liquid chromatography-mass spectrometry

In this study, a sensitive, specific assay for the determination of TNP-470 and its two major metabolites M-IV (also know as AGM-1883) and M-II in human plasma is reported. The assay involves liquid-liquid extraction of acidified plasma followed by reversed-phase high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry. A liquid-liquid extraction using an organic solvent mixture (methyl-tert-butyl-ether-hexane, 1:1, v/v) is used in place of solid-phase extraction because it provides consistent recoveries for all analytes, including the internal standard. Retention times for the analytes and internal standard are less than 7 min. Within- and between-day precision is < or = 6.5% and < or = 13.3% relative standard deviation, respectively, for the three analytes. The lower limits of quantitation are 0.25, 0.5, and 1.0 ng/mL for TNP-470, M-IV, and M-II, respectively.     

超声波提取-气相色谱法测定土壤中21种酚类化合物

建立了超声波提取-气相色谱法同时测定土壤中21种酚类化合物的分析方法。用二氯甲烷和正己烷混合溶剂提取土壤中的酚类化合物,提取液经碱性水溶液分配净化,去除非酸性有机杂质,再酸化萃取酚类化合物,浓缩后采用气相色谱-氢火焰离子化检测器进行检测,外标法定量。以10 g土壤样品计,酚类化合物的检出限为0.01~0.06 mg/kg。实际样品添加回收试验的回收率为62.9%~111.4%,相对标准偏差为4.3%~24.0%(n=6),准确度和精密度均较好。结果表明:该法操作方便,净化效果好,可用于土壤中多种酚类化合物的测定。     

Simultaneous determination of pharmaceuticals, endocrine disrupting compounds and hormone in soils by gas chromatography-mass spectrometry

Analytical methods have been developed for simultaneous determination of six different pharmaceuticals and personal care products (PPCPs) (clofibric acid, ibuprofen, naproxen, ketoprofen, diclofenac, and triclosan), three endocrine disrupting compounds (EDCs) (4-tert-octylphenol, 4-n-nonylphenol, and bisphenol A (BPA)) and one estrogenic compound (estrone) in soil matrix. The soils were extracted by different solvents with the help of an ultrasonic treatment at 42 kHz, followed by a solid phase extraction (SPE) as a cleanup procedure. The purified extracts were derivatized with N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) and then analyzed by GC-MSD (SIM mode). The method was evaluated by testing the following variables: initial spiking levels, extraction solvents, solvent volumes, and soil types (sandy and clay soils). For 5 g of soil, four successive extraction steps with the mixture of acetone-ethyl acetate provided satisfactory recoveries. In the sandy soil, the recoveries of all the compounds were from 63.8 to 110.7% for the spiking level of 100 ng/g dry soil, and from 52.2 to 108.2% for 5 ng/g dry soil, respectively. Result was similar for the clay soil. The precision across all recoveries was high, suggesting that this method has a good reproducibility. The method was successfully employed to soil samples collected from a golf course irrigated with reclaimed wastewater in southern California, and resulted in the detection of clofibric acid, ibuprofen, naproxen, triclosan, bisphenol A, and estrone at ng per gram dry weight concentration levels. The method is robust and simple, and provides straightforward analyses of these current-emerging trace organic pollutants in solid matrices.     

Multiresidue determination of pesticides by solid-phase extraction and GC-MS for control of peach production in Bulgaria

A multiresidue analytical method based on acetone extraction and clean-up/pre-concentration on polymeric sorbents was validated for 42 pesticides in peach matrix in order to control safety of fresh production on the Bulgarian market. Matrix-matched calibration was used by addition of pesticides just before SPE. In this way the standards and the samples undergo exactly the same procedure and an improvement of recoveries for the target analytes was observed. The identification and quantification were done by gas chromatographic technique with mass-spectrometric detection (GC-MS). The limits of detection obtained were 0.005?mg?kg^–1 or lower for the most of analytes, and the recovery data were in range 73–109% at three spiked levels 0.01, 0.1 and 0.2?mg?kg^?1. The validated method was used for monitoring of selected pesticides in fresh peach fruits home production. Approximately 30% of the analysed lots (total 33 samples) contained residues mainly of cypermethrin and procymidone, but did not exceed EU MRLs.