气相色谱-火焰光度法测定土壤中有机磷农药残留

建立了气相色谱-火焰光度(GC-FPD)分析土壤中敌敌畏、氧化乐果、二嗪农、乐果、甲基对硫磷、马拉硫磷、对硫磷、水胺硫磷、喹硫磷等9种有机磷农药残留量的方法。样品用丙酮-二氯甲烷(1:3)提取,浓缩、定容后用Hp-5MS(30m×0.25 mm×0.25μm)毛细管柱分离,FPD检测器检测。方法回收率在68.71%～110.39%之间;RSD在5.5%～11%之间;检出限在0.397～1.60μg/mL之间,方法可用于环境土壤样品中有机磷农药残留的测定。     

固相微萃取/气相色谱-质谱检测纺织品中有机磷农药残留

采用PDMS萃取纤维一次吸附富集纺织品中马拉硫磷、甲基对硫磷、敌敌畏、三唑磷、对硫磷、喹硫磷、二嗪磷7种有机磷农药,在气相色谱-质谱(GC-MS)进样口热解吸后进行定性定量检测。筛选了几种商品化的萃取纤维,并优化了萃取时间、萃取温度、吸附时间、盐浓度以及pH值等萃取条件。本方法操作简单、快速、环保,检出限低,可适用于生态纺织品中物质的快速检测。     

Determination of the residues of eleven organophosphorus insecticides in Job's-tears by gas chromatography with a nitrogen-phosphorus detector

A simplified method for determining 11 organophosphorus insecticides (dichlorvos, methamidophos, acephate, diazinon, dimethoate, chlorpyrifos, malathion, parathion, quinalphos, methidathion, and ethion) in the Chinese herbal medicine Job's-tears is described. Standards were fortified into Job's-tears (5 g) at 4 levels. The organophosphorus insecticides were extracted with dichloromethane and cleaned up with a mixture of Celite 545-activated carbon (4 + 1). The extracts were analyzed by gas chromatography using a nitrogen-phosphorus detector. Analysis of fortified Job's-tears shows average recoveries ranged from 73.90-98.70%, 86.31-93.15%, 84.92-96.22%, and 83.29-104.23% at 0.05, 0.1, 0.5, and 1.0 mg/kg levels, respectively. The minimum detectable amount ranged from 1.0 x 10(-10) to 5.0 x 10(-10) g, and the limit of quantitation for the method was 0.05 mg/kg. The method is rapid, simple, sensitive, reproducible, and applicable to the determination of these 11 organophosphorus insecticides in Job's-tears.     

大葱中25种有机磷农药多残留的微波净化-气相色谱测定

采用微波净化去除大葱中硫醚干扰、气相色谱-火焰光度检测(GC-FPD)实现了大葱基质中25种有机磷农药多残留的快速检测。25种有机磷的加标回收率为85.2%~119.6%,相对标准偏差为2.1%～14.8%。大多数农药在0.1～5.0 mg/L范围内线性关系良好,相关系数不低于0.9910,检出限为0.025~0.200 mg/L。     

QuEChERS Technique for the Gas Chromatographic Determination of Organophosphate Residues in Strawberries

This study describes the validation of an analytical method employing gas chromatography with flame photometric detection for the determination of organophosphate pesticides (diazinon, disulfoton, parathion, chlorpyrifos, and malathion) in strawberries. The method employed a QuEChERS dispersive solid phase extraction for the sample preparation. QuEchERS is inexpensive, fast, and easy for the separation of the analytes from the matrix. In addition, the method provided linear calibration curves, ranging from 0.10–1.00 µg g^?1, for diazinon, disulfoton, parathion, and chlorpyrifos, and 0.10–2.00 µg g^?1 for malathion. Recovery studies yielded values in the range from 81.64 to 100.00%. These results demonstrated the potential of the technique for the determination of organophosphate residues in strawberries.     

基质分散固相萃取-超高效液相色谱-串联质谱法测定蔬菜风险监测中的9种农药残留

建立了基质分散固相萃取-超高效液相色谱-串联质谱测定蔬菜中多菌灵、氧乐果、克百威、涕灭威、毒死蜱、甲胺磷、甲拌磷、对硫磷、甲基对硫磷9种农药残留的方法。蔬菜通过乙腈提取、盐析分配、基质分散固相萃取净化后,采用Waters BEH C18柱(100 mm×2.1 mm, 1.7 μm),以乙腈和0.1%甲酸水溶液作为流动相,梯度洗脱,电喷雾电离正离子(ESI⁺)、多反应监测(MRM)模式测定,基质匹配标准溶液工作曲线法定量。该方法的检出限为0.8~4.0 μg/kg,回收率为72.8%~117.4%。50批蔬菜样品中毒死蜱、多菌灵和氧乐果残留的检出率分别为42.0%、14.0%和2.0%,毒死蜱超标率为8.0%,其他农药未检出。该法可同时测定食品风险监测中蔬菜的农药残留,具有操作方便、准确率高、重复性好等优点,可满足蔬菜中农药残留的检测要求。     

Application of the molecularly imprinted solid-phase extraction to the organophosphate residues determination in strawberries

This study describe an analytical method employing gas chromatography (GC) using flame photometric detection that has been developed for the simultaneous determination of organophosphate pesticides (diazinon, disulfoton, parathion, chlorpyrifos and malathion) in strawberry samples. For this purpose, molecularly imprinted solid-phase extraction was applied as a sample preparation technique. The method was linear in the ranges from 0.10 to 1.00?μg?g^?1, for diazinon, disulfoton, parathion and chlorpyrifos, and 0.10 to 2.00?μg?g^?1 for malathion with r?>?0.99. The detection limits (LD) ranged from 0.02 to 0.05?μg?g^?1. Recovery studies yielded average recoveries in the range of 65.25 to 87.70?%. These results showed the potential of this technique for organophosphate residue monitoring in strawberry samples.     

Simultaneous determination of ten organophosphate pesticide residues in fruits by gas chromatography coupled with magnetic separation

In this study, γ‐Fe₂O₃/chitosan magnetic microspheres were synthesized and evaluated by X‐ray diffraction, SEM, thermogravimetric analysis, and static and kinetic adsorption experiments. Results showed that the magnetic microspheres exhibited good adsorption ability, and offered fast kinetics for the adsorption of trichlorfon, methamidophos, malathion, methyl parathion, dimethoate, omethoate, phosphamidon, phorate, isocarbophos, and chlorpyrifos. Based on magnetic separation, a simple method of magnetic SPE coupled to GC for the simultaneous determination of ten trace organophosphate pesticide residues was developed. Under the optimal conditions, the enrichment factor for ten organophosphorus pesticides was 10.1–364.7 and linear range was 0.001–10.0 mg/L. The LOD (S/N = 3) of the method for the ten pesticides was 0.31–3.59 μg/kg. The RSD for three replicate extractions of spiked samples was between 2.5 and 6.3%. The pear and apple samples spiked with ten organophosphate pesticides at 20 and 200 μg/kg levels were extracted and determined by this method with good recoveries ranging from 79.9 to 98.7%. Moreover, the method has been successfully applied for the determination of the ten organophosphate pesticide residues in peach samples.     

High-performance thin-layer chromatographic analysis of selected organophosphorous pesticide residues in tea

The separation of 9 organophosphates (monocrotophos, quinalphos, triazophos, parathion-methyl, isofenphos-methyl, temephos, parathion, phoxim-ethyl, and chlorpyrifos) by high-performance thin-layer chromatography (HPTLC) with automated multiple development was studied. The HPTLC method was developed and validated for analysis of residues of phoxim-ethyl and chlorpyrifos in tea. The sample was extracted with acetonitrile and cleaned up by ENVI-CARB solid-phase extraction. The extract was directly applied as bands to glass-backed silica gel 60F254 HPTLC plates. The plates were developed with dichloromethane-hexane (1 + 1, v/v) in a glass twin-trough chamber. Evaluation of the developed HPTLC plates was performed densitometrically. The results indicated that the detection limits of phoxim and chlorpyrifos were 5.0 x 10(-9) and 1.0 x 10(-8) g, respectively. Recoveries of the pesticides from tea by this analytical method were 90.7-105.5%, and relative standard deviations were 7.3-13.5%. The precision and accuracy of the method were generally satisfactory for analysis of pesticide residues in tea.     

分散液液微萃取-气相色谱法快速测定水中23种有机磷农药

建立了分散液液微萃取(DLLME)的新型样品前处理方法,并采用气相色谱/火焰光度检测器对饮用水中的治螟磷、甲拌磷、二嗪农、乙拌磷、甲基毒死蜱、甲基对硫磷、皮蝇磷、杀螟松、马拉硫磷、毒死蜱、倍硫磷、对硫磷、溴硫磷、嘧啶磷、甲基异硫磷、稻丰散、杀扑磷、丙溴磷、乙硫磷、三唑磷、三硫磷、哒嗪硫磷、亚胺硫磷23种痕量有机磷农药残...     

Evaluation of a modified QuEChERS method for the extraction of pesticides from agricultural, ornamental and forestal soils

A modified version of the QuEChERS method has been developed for the determination of a group of ten organophosphorus pesticides (i.e. ethoprofos, dimethoate, diazinon, malaoxon, chlorpyrifos-methyl, fenitrothion, malathion, chlorpyrifos, fenamiphos and phosmet) and one thiadiazine pesticide (buprofezin) in three different types of soils (forestal, ornamental and agricultural). The method was validated through linearity, recovery, precision and accuracy studies, and also by carrying out a matrix-matched calibration for the three soils owing to the existence of a strong matrix effect. Acceptable recovery values were obtained (between 45 and 96%) for all the pesticides and soils, except for malathion and malaoxon in forestal and ornamental soils, from which they could not be quantitatively extracted. Limits of detection of the whole method ranged between 0.48 and 7.78 ng/g. The method was finally applied to the determination of chlorpyrifos concentration in a treated soil for cultivation of potatoes.     

Use of SPME extraction to determine organophosphorus pesticides adsorption phenomena in water and soil matrices

Solid-phase micro extraction (SPME) coupled with GC enables rapid and simple analysis of organophosphorus pesticides in a range of complex matrices. Investigations were made into the extraction efficiencies from water of six organophosphorus insecticides (methamidophos, omethoate, dimethoate, parathion methyl, malathion, and parathion ethyl) showing a wide range of polarities. Three SPME fibres coated with different stationary phases, polydimethylsiloxane, polyacrylate, and carbowax-divinylbenzene (CW-DVB), were investigated. Water was spiked with the pesticides at concentrations from 1 to 0.01 µg mL-1, and the solutions used for optimization of the procedure. The CW-DVB fibre, with a 65 µm coating, gave the best performance. The optimized experimental conditions were sample volume 10 mL at 20°C, equilibration time 16 min, pH 5, and presence of 10% w/v NaCl. SPME analyses were performed on solutions obtained by equilibrating aqueous pesticide solutions with six certified soils with various physico-chemical characteristics. SPME data were also assessed by comparison with analyses performed by using conventional solid-phase extraction. Results indicate the suitability of SPME for analysis of pesticides in environmental water samples.     

Simple determination of 22 organophosphorous pesticides in human blood using headspace solid-phase microextraction and gas chromatography with mass spectrometric detection

A simple and rapid procedure for the determination of 22 organophosphorous pesticides (bromophos-ethyl, bromophos-methyl, chlorfenvinphos, chlorpyriphos, demethon-S-methylsulfon, diazinon, dichlorvos, dicrotophos, dimethoate, disulfoton, edifenphos, fenitrothion, fenthion, malathion, methidathion, mevinphos, monocrotophos, omethoate, parathion-ethyl, parathion-methyl, phosphamidon, and quinalphos) in human blood using headspace (HS) solid-phase microextraction (SPME) and gas chromatography (GC)-mass spectrometry (MS) is presented. The effects of various sample additions, incubation temperatures, absorption times, desorption times, and depths of fiber insertion into the injection port of the GC are optimized to enhance the sensitivity of the procedure. The recoveries of spiked blood samples are determined between 70% and 95% compared with samples prepared in water, and absolute recoveries are in the range between 0.1% and 19.6%. For quantitation in the single ion monitoring mode, linearity is established over concentration ranges from 0.025 to 5.0 microg/g with excellent coefficients of correlation (0.991-0.998). The detection limits are in the range between 0.01 and 0.3 microg/g. The time for analysis is 44 min per sample including extraction and GC-MS analysis. HS-SPME in combination with GC-MS is an effective method for the determination of organophosphorous pesticides in human blood and shows a great potential for use in rapid on-site analytical work, which is highly demanded in clinical and forensic toxicology.     

多壁碳纳米管-固相萃取分析有机磷农药残留

建立了多壁碳纳米管为吸附剂的固相萃取净化和火焰光度检测气相色谱法测定蔬菜中16种有机磷农药的方法.采用双柱双检测器进行定性和定量分析.建立了水相和有机相上样两种净化体系.水相上样时采用pH 5.0醋酸-醋酸钠缓冲体系,真空抽干除水,二氯甲烷为洗脱剂,只有9种农药的回收率>75%.对于正己烷溶解药物,丙酮-正己烷(5: 5,V/V)作洗脱剂的有机相净化体系,16种农药回收率均>75%.本研究提出的有机相上样净化体系用于黄瓜、卷心菜、韭菜、生姜和洋葱等样品的净化,效果良好,表明多壁碳纳米管具有较强的吸附和去除色素的能力,可以克服色素对测定的干扰.     

Rapid clean-up of fat extracts for organophosphorus pesticide residue determination using C18 solid-phase extraction cartridges

Commercial solid-phase extraction (SPE) cartridges with C₁₈ bonded silica packings effectively cleaned up acetonitrile extracts of 3-g samples of fats and oils for determination of organophosphorus pesticide residues by gas chromatography with flame photometric detection. Cartridges from three different sources were tested and found to differ in lipid capacity and inertness (free silanol activity). Consequently, the amount of packing (i.e., number of cartridges) and/or the choice of eluent used were adjusted for each brand of cartridge to achieve optimum clean-up and analyte recovery. Seven pesticides with a wide range of polarity (acephate, azodrin, chlorpyrifos, diazinon, malathion, methamidophos and methyl parathion) were separated from coextracted lipids by elution with either acetonitrile or methanol, depending on the brand of cartridge used. Cartridges were regenerated by purging lipids with dichloromethane and were reused numerous times without apparent loss of effectiveness. Recoveries from vegetable oils and butterfat fortified with the seven compounds at levels of 0.05–0.87 μg g^?1 ranged from 80 to 103%. Practical limits of determination range from 0.01 to 0.08 μg g^?1, depending on analyte response.     

Determination of insecticides in honey by matrix solid-phase dispersion and gas chromatography with nitrogen-phosphorus detection and mass spectrometric confirmation

A multiresidue method was developed for the determination of 12 organophosphorus insecticides (diazinon, parathion methyl, fenitrothion, pirimiphosmethyl, malathion, fenthion, chlorpyrifos, quinalphos, methidathion, ethion, azinphosmethyl, coumaphos), one carbamate (pirimicarb), and one amidine (amitraz) in unifloral and multifloral honeys. The analytical procedure was based on the matrix solid-phase dispersion of honey on a mixture of Florisil and anhydrous sodium sulfate in small glass columns and subsequent extraction with a low volume of hexane-ethyl acetate (90 + 10, v/v), assisted by sonication. The insecticide residues were determined by capillary chromatography with nitrogen-phosphorus detection and confirmed by mass spectrometry. Average recoveries at the 0.05-0.5 microg/g levels were >80% for organophosphorus insecticides and about 60% for the other insecticides, pirimicarb and amitraz, with relative standard deviations <10%. The detection limit for the different insecticides ranged between 6 and 15 microg/kg. The main advantages of the proposed method are that extraction and cleanup are performed in a single step with a low volume of organic solvent. The method is simple, rapid, and less laborious than conventional methods. Several Spanish honeys were analyzed with the proposed method and no residues of the studied insecticides were found.     

固相萃取–毛细管气相色谱法同时测定水体中8种有机磷类农药残留

建立固相萃取–毛细管气相色谱法同时测定水体中敌敌畏、乙酰甲胺磷、治螟磷、乐果、甲基对硫磷、马拉硫磷、杀螟硫磷和水胺硫磷8种有机磷类农药残留。样品经OASIS HLB固相萃取柱富集,丙酮洗脱,用毛细管气相色谱(FPD)法进行定量分析。8种有机磷类农残留的质量浓度在0.05~4.0μg/m L范围内与色谱峰面积线性关系良好,相关系数均大于0.998,方法检出限为0.004~0.01μg/m L。测定结果的相对偏差为2.6%~4.5%(n=6),加标回收率为81.6%~106.2%。该方法操作简单、灵敏度高,可用于检测水体中的8种有机磷类农药残留。     

A liquid chromatography/electrospray ionization-tandem mass spectrometry method for quantification of specific organophosphorus pesticide biomarkers in human urine

Organophosphorus pesticides are commonly used in both agricultural and residential settings. The widespread use of these chemicals makes it almost impossible for humans to avoid exposure. In order to determine background human exposure, there is a need for fast, reliable, and sensitive analytical methods. We have developed a sensitive method to quantify specific biomarkers of the organophosphorus pesticides acephate, azinphos, chlorpyrifos, coumaphos, diazinon, isazofos, malathion, methamidophos, parathion and pirimiphos or their O,O-dimethyl analogues in human urine, as their selective metabolites or as the intact pesticide. Isotopically labeled internal standards were used for eight of the analytes. The use of labeled internal standards in combination with high-performance liquid chromatography electrospray ionization–tandem mass spectrometry provided a high degree of specificity. Repeated analysis of urine samples fortified with high and low concentrations of the analytes gave relative standard deviations (RSD) of less than 10% for the analytes with an isotopically labeled standard. Analytes without isotopically labeled standards had higher RSD. For all compounds except methamidophos and acephate, the recoveries were greater than 70%. The limits of quantification for most of the analytes were in the range of 0.1 to 1 ng/mL. We detected concentrations of most of these pesticides and/or their metabolites in urine samples from non-occupationally exposed persons using our method. Our frequencies of detection for the analytes measured ranged from 1% to 98%.     

Simultaneous determination of three organophosphorus pesticides in different food commodities by gas chromatography with mass spectrometry

A sensitive and selective gas chromatography with mass spectrometry method was developed for the simultaneous determination of three organophosphorus pesticides, namely, chlorpyrifos, malathion, and diazinon in three different food commodities (milk, apples, and drinking water) employing solid‐phase extraction for sample pretreatment. Pesticide extraction from different sample matrices was carried out on Chromabond C₁₈ cartridges using 3.0 mL of methanol and 3.0 mL of a mixture of dichloromethane/acetonitrile (1:1 v/v) as the eluting solvent. Analysis was carried out by gas chromatography coupled with mass spectrometry using selected‐ion monitoring mode. Good linear relationships were obtained in the range of 0.1–50 μg/L for chlorpyrifos, and 0.05–50 μg/L for both malathion and diazinon pesticides. Good repeatability and recoveries were obtained in the range of 78.54–86.73% for three pesticides under the optimized experimental conditions. The limit of detection ranged from 0.02 to 0.03 μg/L, and the limit of quantification ranged from 0.05 to 0.1 μg/L for all three pesticides. Finally, the developed method was successfully applied for the determination of three targeted pesticides in milk, apples, and drinking water samples each in triplicate. No pesticide was found in apple and milk samples, but chlorpyrifos was found in one drinking water sample below the quantification level.     

Simultaneous separation and determination of eight organophosphorous pesticide residues in vegetables through molecularly imprinted solid‐phase extraction coupled to gas chromatography

How to determine the multipesticide residues in vegetables is an important problem. In this study, a new molecularly imprinted polymer was synthesized using O,O‐dimethyl thiophosphoryl chloride, an intermediate for the manufacture of organophosphorous pesticides, as the template. Characterization test indicated that the synthesized polymer exhibited good recognition and selectivity for dichlorvos, methamidophos, acephate, folimat, monocrotophos, parathion‐methyl, phosphamidon, and malathion. A molecularly imprinted SPE coupled to GC for simultaneous separation and determination of eight organophosphorous pesticides residues was developed. Under optimal conditions, the linear range of this method was 0.001–10.0 mg/L. The LOD of this method was in the range of 0.13–0.90 μg/kg. With a flow rate of 2.5 mL/min for loading 100 mL, the enrichment factor in the range of 25–480 for the eight organophosphorous pesticides was obtained. The RSD of the eight organophosphorous pesticides based on five replicates was from 1.50 to 4.09%. The accuracy of the proposed method was evaluated by recovery measurements on spiked samples, and good recovery rates ranging from 80.11 to 97.70% were achieved. Moreover, this method was evaluated for the quantitative detection of eight organophosphorous pesticide residues in leek and pakchoi samples.