HP－50＋大口径毛细管气相色谱法测定水果中多种有机氯农药残留量

以ＨＰ－５０＋大口径毛细管柱为分离柱，ＧＣ－ＥＣＤ测定水果中１４种有机氯农残。方法的检测限为０．１×１０￣（－９）～２．０×１０￣（－９），回收率范围在８８．６％～１０５．８％，变异系数２．６％～１０．５％。样品前处理采用微量化学法。     

快速气相色谱法测定蔬菜中菊酯类农药残留量

采用一种较快速，简单的方法测定蔬菜中菊酯类农药残留物。样本中农残经乙酸酯萃取，凝胶渗透色谱及固相提取净化后，用气相色谱－电子捕获检测器测定，色谱柱为ＨＰ－５小口长石英毛细管柱。本法对６种常用菊酯类农药的回收率范围为８９．６％－９９．７％，检测限为０．０４ｍｇ／ｋｇ。对同一批普施用菊酯类农药的白菜样本进行化验，本法跟美国食物及药品管理局农药残留标准测定方法所得结果非常吻合。     

水果、蔬菜中16种有机氯残留农药的毛细管气相色谱测定法

采用柱层析净化方式,以ＨＰ－１０１弹性石英毛细管柱为分离柱,电子捕获检测的气相色谱法测定水果、蔬菜中１６种有机氯农药残留量。方法的检出限为０．１×１０－９～２．０×１０－９,回收率范围在８７．５％～１０６．３％之间,相对标准偏差为３．０％～９．５％。     

毛细管色谱法测定果蔬中22种有机磷农药残留量

果蔬中２２种有机磷农残用ＣＧＣ－ＦＰＤ测定。采用带有电子压力控制（ＥＰＣ）的新型进样口系统，以电子压力编程（ＥＰＰ）方式控制载气流速，具有更高的检测灵敏度。用ＢＰ－１０毛细管柱为分离柱，２２种有机磷农药在４０ｍｉｎ内获得良好分离。本法对２２种有机磷农残的回收率范围为８２．５％～１０５．６％，变异系数为３．４％～１５．２％，检测限为０．１～２０×１０（－９）。     

快速气相色谱法测定蔬菜中甲胺磷和水胺硫磷残留量

蔬菜中甲胺磷和水胺磷残余经氯仿萃取后，用气相色谱－火焰光度检测器（ＧＣ－ＦＰＤ）直接测定，色谱柱为ＤＢ－１７大口径石英毛细管柱，采用气相色谱－离子阱质谱系统检测样品中的甲胺磷和水胺硫磷，在三个不同含量水平的收率试验中，本法的回收率为９３．６％－１０４．１％，最低检测限可达０．０６μｇ／ｇ     

大口径毛细管气相色谱法测定果蔬中15种有机氯农药残留量

果蔬样品中１５种有机氯农残用丙酮－石油醚提取，经含５％Ｈ２Ｏ的浓硫酸磺化离心净化，ＧＣ－ＥＣＤ测定。色谱柱为ＨＰ－５０＋大口径毛细管柱，方法的回收率为８５．７～１０８．５％，变异系数４．８～１２．６％。     

鸦片的气相色谱快速分析

采用大口径毛细管柱,建立了一种气相色谱测定鸦片中生物碱的快速分析方法。样品经超声提取,ＨＰ－１（５ｍ×０．５３ｍｍ×２．６５μｍ）毛细管色谱柱,ＦＩＤ测定。回收率为９６．８％￣１０１．１％,相对标准偏差均小于３％。方法简便,快速,准确,灵敏。     

用气相色谱法测定粮谷和油籽中氯苯胺灵残留量

确立了粮谷和油籽中氯苯胺灵残留量的气相色谱测定方法，试样采用甲醇提取，经与正己烷液液分配，再以弗罗里硅土柱净化，毛细管柱气相色谱－氮磷检测器测定。方法简便、准确、检出限０．０２μｇ／ｇ，添加回收率为８７．５－９２．９％，相对标准偏差为３．５－７．０％。     

用大口径毛细管柱气相色谱法测定蜂蜜中杀虫脒残留量

蜂蜜中杀虫脒残留量用气相色谱－氮磷检测器（ＧＣ－ＮＰＤ）直接测定，色谱柱为ＨＰ－５大口径毛细管柱，方法的回收率为７８．３％～９２．５％，变异系数为４．２％，最低检测限２×１０－９。样品前处理采用了微量化学法。     

氢化物－气相色谱的元素光度检测器

研究开发的一种新型的元素光度检测器主要用于锗、砷、锡和锑的氢化物气相色谱检测，具有高灵敏，高选择性。它是在普通火焰光度检测器的基础上加装了特制的滤光片改制而成的。对锗、砷、锡和锑的检测限分别为３．０×１０￣（－１１）ｇ、７．０×１０￣（－１１）ｇ、７．０×１０￣（－１０）ｇ和１．１×１０￣（－８）ｇ，相对标准偏差分别为１．８％、２．４％、２．６％和３．０％。     

Determination of pesticides by solid phase extraction followed by gas chromatography with nitrogen–phosphorous detection in natural water and comparison with solvent drop microextraction

The European Union specificies that drinking water can contain pesticide residues at concentrations of up to 0.1 μg/L each and 0.5 μg/L in total, and that 1–3 μg/L of pesticides can be present in surface water, but the general idea is to keep discharges, emissions and losses of priority hazardous substances close to zero for synthetic substances. Therefore, in order to monitor pesticide levels in water, analytical methods with low quantification limits are required. The method proposed here is based on solid phase extraction (SPE) followed by gas chromatography with a nitrogen–phosphorous detector (GC-NPD). During method development, six organophosphate pesticides (azinphos-ethyl, chlorfenvinphos, chlorpyriphos, ethoprophos, fenamiphos and malathion) and two organonitrogen pesticides (alachlor and deltamethrin) were considered as target analytes. Elution conditions that could influence the efficiency of the SPE were studied. The optimized methodology exhibited good linearity, with determination coefficients of better than 0.996. The analytical recovery for the target analytes ranged from 70 to 100%, while the within-day precision was 4.0–11.5 %. The data also showed that the nature of the aqueous matrice (ultrapure, surface or drinking water) had no significant effect on the recovery. The quantification limits for the analytes were found to be 0.01–0.13 μg/L (except for deltamethrin, which was 1.0 μg/L). The present methodology is easy, rapid and gives better sensitivity than solvent drop microextraction for the determination of organonitrogen and organophosphate pesticides in drinking water at levels associated with the legislation.     

Simultaneous kinetic determination of chlorpyrifos and carbaryl based on differential degradation processes in alkaline oxidative medium

A kinetic method for the simultaneous determination of chlorpyrifos and carbaryl is described. The method is based on the degradation of these compounds in alkaline hydrogen peroxide medium by measuring the absorbance at two different reaction times and at two different wavelengths. A homemade stopped-flow system coupled with a diode-array detector and the proportional equation method was used. Resolution was achieved over chlorpyrifos: carbaryl ratios ranging from 61 to 14, with relative errors of 4 and 3%, respectively. The method was successfully applied to the analysis of a commercial formulation.     

Development of liquid phase microextraction method based on solidification of floated organic drop for extraction and preconcentration of organochlorine pesticides in water samples

A simple and efficient liquid-phase microextraction (LPME) in conjunction with gas chromatography-electron capture detector (GC-ECD) has been developed for extraction and determination of 11 organochlorine pesticides (OCPs) from water samples. In this technique a microdrop of 1-dodecanol containing pentachloronitrobenzene (internal standard) is delivered to the surface of an aqueous sample while being agitated by a stirring bar in the bulk of solution. Following completion of extraction, the sample vial was cooled by putting it into an ice bath for 5 min. Finally 2 μL of the drop was injected into the GC for analysis. Factors relevant to the extraction efficiency were studied and optimized. Under the optimized extraction conditions (extraction solvent: 1-dodecanol; extraction temperature: 65 °C; sodium chloride concentration: 0.25 M; microdrop and sample volumes: 8 μL and 20 mL respectively; the stirring rate: 750 rpm and the extraction time: 30 min), figures of merit of the proposed method were evaluated. The detection limits of the method were in the range of 7-19 ng L⁻¹ and the RSD% for analysis of 2 μg L⁻¹ of OCPs was below 7.2% (n = 5). A good linearity (r² ≥ 0.993) and a relatively broad dynamic linear range (25-2000 ng L⁻¹) were obtained. After 30 min of extraction, preconcentration factors were in the range of 708-1337 for different organochlorine pesticides and the relative errors ranged from −10.1 to 10.9%. Finally the proposed method was successfully utilized for preconcentration and determination of OCPs in different real samples.     

气相色谱法测定黄芪饮片中有机氯类农药残留

采用气相色谱电子捕获检测器(ECD)测定黄芪饮片中9种有机氯类农药残留。黄芪饮片样品以丙酮、二氯甲烷提取,浓硫酸磺化,采用HP–5(30 m×0.32 mm,0.25μm)色谱柱,气化室温度为250℃,检测器温度为300℃。以标准曲线法计算农药含量,加标回收率为94.5%~104.4%,测定结果的相对标准偏差为1.7%~2.7%,检出限为0.061~0.175 ng/m L。该方法简单、快速、稳定、可靠,可用于黄芪饮片中9种有机氯类农药残留的测定。     

Sulfonic acid-based metal organic framework functionalized magnetic nanocomposite combined with gas chromatography-electron capture detector for extraction and determination of organochlorine

The metal organic framework functionalized with sulfonic acid was combined with magnetic nanoparticles to fabricate a new nanocomposite (denoted as Fe₃O₄@PDA@Zr-SO₃H). By combining with gas chromatography-electron capture detector, the resulting Fe₃O₄@PDA@Zr-SO₃H nanocomposite was successfully used as a high-efficiency adsorbent for pre-concentrating eight organochlorine pesticides from water sample in environment. Apart from the ability of fast separation, the as-prepared Fe₃O₄@PDA@Zr-SO₃H nanocomposite also exhibited high adsorption capacity for organochlorine pesticides. With the use of optimal experimental conditions, the linear relationship can be obtained in the range of 0.05∼300 μg/L, the correlation coefficient was over 0.9978, and the relative standard deviation was located in 2.5%–7.7%. Moreover, the limit of detection and quantification was between 0.005–0.016 μg/L and 0.017∼0.050 μg/L. Finally, the nanocomposite was used for the determination of organochlorine pesticides from environmental water samples, and displayed the recovery of 82%–118%.     

Gas chromatography with surface ionization detection of nitro pesticides

A surface ionization gas chromatographic detector, based upon positive surface ionization, was used in capillary gas chromatography to sensitively and selectively detect nitro pesticides: pendimethalin, trifluralin, flumetralin. Higher sensitivity (better detection limit), substance specificity, and advantageous applicability are reported. Sensitivity to pendimethalin, trifluralin, and flumetralin was 1.4 C g⁻¹, 1.1 C g⁻¹, and 1.0 C g⁻¹, respectively, with the linear range of operation greater than 1 × 10⁵ for these compounds. The minimum detectable level was in the range of 10⁻¹³ g s⁻¹. Compared with an atomic emission detector, SID provided a 110 times better detection limit for trifluralin.     

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.     

A novel headspace solid-phase microextraction method for the exact determination of organochlorine pesticides in environmental soil samples

A novel method of determining organochlorine pesticides (OCPs) is described. It is based on solid-phase microextraction (SPME) and gas chromatography–electron capture detection. During the development of the method, soil samples were prepared, spiked with standard solution, and then aged for some time. Extraction conditions such as the extraction time, the NaCl content, the volume of water, the extraction temperature and the desorption time were investigated and optimized. The limits of detection obtained using the method ranged from 0.10 to 0.51 ng g⁻¹, and relative standard deviations were lower than 10% for most organochlorine pesticides. Real soil samples were successfully analyzed using the proposed method. The results from the method developed here were in good agreement with those obtained using ultrasonic extraction. The result demonstrates that aging soils spiked with standard solution is an important method development step, because the soil samples obtained using this approach are more like real soils than those obtained when aging is not used.      

Determination of pyrethroid,organophosphate and organochlorine pesticides in water by headspace solid-phase microextraction

Simultaneous determination of pyrethroid, organophosphate (OP) and organochlorine (OC) pesticides in water was achieved with headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-electron-capture detection (GC-ECD). The parameters affecting HS-SPME of pesticides from water were optimized, including extraction temperature, sample and headspace volumes, and sodium chloride amounts. The effects of desorption temperature, desorption time, and position of the fibre in the GC inlet were also investigated. Extraction temperature was the most important factor affecting the recoveries of analytes, and the optimized temperature was 96°C. The addition of salt did not increase extraction efficiencies of the pesticides from the water. The optimized desorption conditions in the GC were as follows: desorption time of 10?min; desorption temperature of 260°C; and a 2?cm position of the fibre in the inlet. The method detection limits were in the low-ng/L level with a linearity range of 50–1000?ng/L for the OCs, 50–5000?ng/L for the OP, and 50–20?000?ng/L for the pyrethroids. These data demonstrated that HS-SPME is a sensitive method for the determination of pyrethroid, OC, and OP pesticides in water.     

Pesticide residues analysis in honey using ethyl acetate extraction method: validation and pilot survey in real samples

This paper presents a cost-effective and validated multi residue confirmatory method for the determination of 167 chemically different pesticides and a survey study on Cyprus honey samples. This method uses ethyl acetate for the extraction of pesticides from honey and the determination is performed with liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS) and with GC–ECD (gas chromatography with electron capture detector) analysis. The LC-MS/MS analytical system is especially important in the analysis of polar and non-volatile pesticides. For the validation of the method, blank honey samples were spiked with 146 pesticides (organophosphorous, carbamates, triazoles, amides, neonicodinoids, strobilurines, phenylureas, bendimidazoles and others) for the LC-MS/MS analysis at three levels: 0.01, 0.05 and 0.1 mg kg^?1 and with 21 pesticides for the GC-ECD analysis at two levels: 0.01 and 0.05 mg kg^?1for organochlorines and 0.05 and 0.2 mg kg^?1for the pyrethroids. As blank sample, a sample of honey which did not contain detectable levels of the analytes sought was used. The validation study was in accordance to the DG SANCO guidelines. The scope of validation included recovery, linearity, limits of quantification and precision. Linearity is demonstrated all along the range of concentration that was investigated with correlation coefficients ≥0.98. Recoveries of the majority of compounds were in the 70%–120% range and were characterised by precision lower or equal to 20%. The validated method was used for a survey of 36 samples of honey produced in different areas of Cyprus and this is the first work on Cypriot honey samples investigating a broad range of pesticides. Only coumaphos was detected at concentrations higher than 0.01 mg kg^?1 in the 58.6% of the honey samples analysed for Coumaphos. The results were evaluated in accordance to the provisions of the Commission Regulation (EU) No 37/2010 on pharmacologically active substances and their classification regarding maximum residue limits (MRLs) in foodstuffs of animal origin. The concentrations of coumaphos in all positive samples were at levels much lower than the MRL.