高效液相色谱法分析水稻和稻田中的氯硝柳胺乙醇胺盐残留

建立了高效液相色谱(HPLC)测定水稻和稻田中氯硝柳胺乙醇胺盐残留量的分析方法。稻田水和稻秆样品中的氯硝柳胺乙醇胺盐残留用碱性乙酸乙酯直接提取;而稻田土壤、糙米和谷壳样品则先经碱性乙醇提取,再用乙酸乙酯进行萃取。萃取物经弗罗里硅土柱净化后,经Welchrom C18柱分离,采用紫外检测器检测,外标法定量。在0.01～10.00 mg/L范围内,氯硝柳胺乙醇胺盐的峰面积与其质量浓度间呈良好的线性关系,相关系数为0.9998。在稻田水、土壤、稻秆、糙米和谷壳中添加0.01～5.00 mg/kg的氯硝柳胺乙醇胺盐,其平均回收率为93.47%～100.9%,相对标准偏差为1.46%～5.82%,符合农药残留量分析与检测的技术要求。该方法简便、快速,灵敏度高,重现性好,可用于环境系统中氯硝柳胺乙醇胺盐残留量的分析与检测。     

洋葱中多种农药残留的双柱双检测器气相色谱分析法

洋葱中含有许多对人类有用的成分包括:水分、蛋白、脂肪、膳食纤维、碳水化合物、胡萝卜素、视黄醇、硫胺素、核黄素、抗坏血酸、维生素总E、K、Na、Ca、Mg、Fe、Mn、Zn等[1].近来的许多研究表明,洋葱具有消炎抑菌,预防心血管疾病、糖尿病等生物活性[2].由于洋葱的医疗价值和保健作用,洋葱现在已经成为人们喜爱的蔬菜,受到人们的重视,尤其在欧美,洋葱被称为"蔬菜皇后".目前,国内外对洋葱的研究越来越多,但是主要集中在研究它的生物活性和成分上[2-4].由于洋葱中合有油类物质,因此给农药残留分析带来许多困难.至今,对洋葱中的农药残留分析还未有成熟的方法.目前,用气相色谱分析多组分农药残留的报道已经有了很多[5,6],关于用双检测器分析多组分农药残留的研究,已越来越引起研究人员的关注[7-9].Jatiender Kumar Dubey等[7]用GC-NPD和GC-ECD检测了食品中乙烯基硫脲的含量.Jiménez等[8]利用GC-NPD和GC-ECD分析了蜂蜜中的农药残留.但是用GC-FPD和GC-ECD分析洋葱中的农药残留还未见报道.本文报道了一种简便、快速的洋葱中多种有机磷和菊酯类农药残留的提取净化及其双柱双检测器测定方法.采用乙睛提取洋葱中的农药,二氯甲烷/乙酸乙酯(20:1,V:V)为淋洗剂,经过Florisil和活性炭净化后,用气相色谱-火焰光度检测器和气相色谱-电子捕获检测器分别直接测定各种农药残留含量.结果表明,采用程序升温,所测定的有机磷和菊酯类农药在DB-1701和BPX608弹性石英毛细管柱上得到了很好的分离,且方法快速、灵敏,完全符合实际应用需要.各种农药的加标回收率范围为86.3～103%,变异系数范围为0.67～4.6%,最低检测浓度范围为0.001～0.005 mg/kg.     

Solid‐phase nanoextraction of polychlorinated biphenyls in water and their determination by gas chromatography with electron capture detector

A solid‐phase nanoextraction method has been developed for the extraction and preconcentration of polychlorinated biphenyls using carboxyl multiwalled carbon nanotubes as a solid nano‐sorbent. Parameters affecting extraction efficiency such as sorbent amount, desorption solvent type and volume, extraction time, pH, and salt content have been studied. Under optimized conditions, the correlation coefficient was up to 0.9989, the limits of detection was in the range of 1.4–3.5 ng/L, and limits of quantification was between 4.8 and 11.6 ng/L. The recoveries were in the range of 99–106% for different spiked analytes. The relative standard deviation for water samples spiked with two different spiking levels has been between 4 and 10%. The proposed sustainable method is rapid, easy to use, and small consumption of organic solvent for the detection and determination of trace levels of polychlorinated biphenyls in environmental waters.     

气相色谱-电子捕获检测法测定海水中十氯酮残留

通过考察提取溶剂、毛细管柱、净化条件及共溶出干扰物等因素对十氯酮测定的影响,建立了二氯甲烷液-液富集萃取、硫酸净化分离、气相色谱法(GC)-电子捕获检测器(ECD)测定海水介质中有机氯农药类持久性有机污染物十氯酮残留分析方法。1 L海水经50 mL二氯甲烷萃取富集,浓缩后采用硫酸净化,以1%(体积分数)甲醇/正己烷混合溶液转移定容后,采用DB-5非极性毛细管柱进行GC分离,电子捕获检测器可测定其中十氯酮的含量;该方法采用外标法定量,在5～100 μg/L范围内呈线性,线性相关系数为0.9989。低、中、高3个浓度水平的平均加标回收率为81%～108%,相对标准偏差为1.2%～5.1%(n=6)。方法的检出限为0.6 ng/L。结果表明,该方法灵敏度高,线性关系好,可以满足简便、快速、准确测定海水中十氯酮的要求。     

Rapid determination of acrylamide contaminant in conventional fried foods by gas chromatography with electron capture detector

Gas chromatography coupled with electron capture detector (GC-ECD) was successfully developed and applied for the rapid determination of acrylamide in conventional fried foods, such as potato crisps, potato chips, and fried chicken wings. The method included defatting with n-hexane, extraction with aqueous solution of sodium chloride (NaCl), derivatization with potassium bromate (KBrO3) and potassium bromide (KBr), and liquid-liquid extraction with ethyl acetate. The final acrylamide extract was analyzed by GC-ECD for quantification and by GC-MS for confirmation. The chromatographic analysis was performed on the HP-INNOWax capillary column, and good retention and peak response of acrylamide were achieved under the optimal conditions (numbers of theoretical plates N = 83,815). The limit of detection (LOD) was estimated to be 0.1 microg kg(-1) on the basis of ECD technique. Recoveries of acrylamide from conventional samples spiked at levels of 150, 500 and 1000 microg kg(-1) (n = 4 for each level) ranged between 87 and 97% with relative standard deviations (RSD) of less than 4%. Furthermore, the GC-ECD method showed that no clean-up steps of acrylamide derivative would be performed prior to injection and was slightly more sensitive than the MS/MS-based methods. Validation and quantification results demonstrated that this method should be regarded as a new, low-cost, and robust alternative for conventional investigation of acrylamide.     

Determination of chloramphenicol residue in chicken tissues by immunoaffinity chromatography cleanup and gas chromatography with a microcell electron capture detector

A rapid and sensitive gas chromatography (GC) method was developed to detect chloramphenicol in chicken tissues. The extracted samples were cleaned up using the immunoaffinity column prepared by coupling antichloramphenicol monoclonal antibody with cyanogen bromide-activated Sepharose 4B. The dynamic column capacity of chloramphenicol was 3265 ng/mL gel. The eluate was evaporated to dryness, and residues were derivatized and determined by GC with a microcell electron capture detector. Average recoveries were 86.6 to 96.9% for chicken muscle and 74.3 to 96.1% for chicken liver. The limit of quantitation of the method was 0.05 ng/g for chicken muscle and 0.1 ng/g for chicken liver.     

The use of the electron capture detector in human and equine doping analysis by gas chromatography

Summary The possibilities, applications and limitations of the electron capture detector (ECD) in human and equine doping analysis are considered. As many stimulants and/or their metabolites possess and amino group the introduction of halogen containing groupings by acylation results in improved chromatographic performance almost combined with enhanced sensitivity and selectivity when using the ECD. Several examples of the confirmation of doping agents like amphetamines, ephedrine, phenylbutazone, pemoline and procaine by GC/ECD are given.Presented at the 7^th International Symposium on Biomedical Applications of Chromatography, Hradec Králové, Czechoslovakia; 6–9 Sept. 1982.     

Determination of chloramphenicol residue in fish and shrimp tissues by gas chromatography with a microcell electron capture detector

A gas chromatography method with microcell electron capture detection was developed for the determination of chloramphenicol residue in fish and shrimp muscle tissues. The tissue samples were extracted with ethyl acetate, defatted with hexane, and derivatized with Sylon BFT [N,O-bis (trimethylsilyl) trifluoroacetamide-trimethylchlorosilane (99 + 1)]. The limit of detection was 0.04 ng/g and the limit of quantitation 0.1 ng/g. Average recoveries were 70.8-90.8% for fish and 69.9-86.3% for shrimp, respectively. The method was validated for the determination of practical samples.     

Precision of an automated all-glass capillary gas chromatography system with an electron capture detector for the trace analysis of estrogens

Subnanogram detection of steroids has become increasingly important today. One applicable method for gas chromatographic determination of subnanogram quantities of estrogens as halogenated derivatives is electron capture detection. HFB-derivatives of 7 different estrogens were automatically injected onto a prolonged narrow bore wall-coated glass capillary column. Normal split injection could not be used for this trace analysis because of too much loss of sample. Only small amounts of sample were available from which double analysis had to be performed. Cross-contamination of the automatic sampling system as well as precision of retention times and peak areas were determined. The type of injection described showed better quantitative results compared to the splitless injection technique. All details of the system used together with the results are this discussed in this paper.     

气相色谱-微池电子捕获器检测尿液中的三唑仑

建立了气相色谱-微池电子捕获检测器(GC-μECD)检测尿液中三唑仑的方法。筛选了pH值、提取溶剂、涡旋时间,优化了液-液萃 取条件。在0.2～50 ng/mL范围内,线性关系良好,相关系数为0.9995;方法的检出限为0.1 ng/mL,日内和日间测定的相对标准偏差分 别为4.17%和5.31%,平均回收率为93.9%。该方法操作简便、灵敏度高、线性范围广、回收率高,完全能够满足日常检测工作的需要。     

Risk assessment,dissipation behavior and persistence of quinalphos in/on green pea by gas chromatography with electron capture detector

Chemical investigation was carried out to examine the risk assessment, dissipation behavior, persistence, and half‐life period of quinalphos in/on green pea fruit by spraying quinalphos at fruiting stage followed by another application after 10‐day interval. The samples were extracted by using the quick, easy, cheap, effective, rugged, and safe method, and the residues of quinalphos were analyzed by gas chromatography with electron capture detector. Herein, we report a novel, accurate, and cost‐effective gas chromatography method for the determination of average deposits of quinalphos in/on green pea. The initial deposits and half‐life of quinalphos were found to be 1.20 mg/kg and 2.77 days, respectively, following the application of insecticide. Residues of quinalphos reached below detection limit of 0.05 mg/kg after 10 days at recommended dosage. For risk assessment studies, the tenth day will be safe for consumers for consumption of green pea. The developed method is simple, selective, and repeatable, and it can be extended for quinalphos‐based standardization of herbal formulations containing green pea and its use in pesticide industries.     

Quantification,dissipation behavior and risk assessment of ethion in green pea by gas chromatography‐electron capture detector

Residue investigation was carried out to scrutinize the persistence, dissipation behavior, half‐life, and risk assessment of ethion on green pea fruit by spraying ethion at the fruiting stage followed by another application at 10 day intervals. The samples were extracted by using a quick, easy, low‐cost, effective, rugged, and safe method, and the residues of ethion were analyzed by gas chromatography with electron capture detection. Here we report a novel, accurate, and cost‐effective gas chromatography method for the determination of average deposits of ethion on green pea. The initial deposits were found to be 4.65 mg/kg following the application of insecticide. Residues of ethion reached below the detection limit of 0.10 mg/kg after 25 days at recommended dosage. The half‐life of ethion was found to be 4.62 days. For risk assessment studies, the 25th day will be safe for consumers for the consumption of green peas. The developed method is simple, sensitive, selective, and repeatable and can be extended for ethion‐based standardization of herbal formulations containing green pea and its use in pesticide industries.     

Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and an electron capture detector

Hazardous waste site characterization, forensic investigations, and land mine detection are scenarios where soils may be collected and analyzed for traces of nitroaromatic, nitramine, and nitrate ester explosives. These thermally labile analytes are traditionally determined by high-performance liquid chromatography (HPLC); however, commercially available deactivated injection port liners and wide-bore capillary columns have made routine analysis by gas chromatography (GC) possible. The electron-withdrawing nitro group common to each of these explosives makes the electron capture detector (ECD) suitable for determination of low concentrations of explosives in soil, water, and air. GC-ECD and HPLC-UV concentration estimates of explosives residues in field-contaminated soils from hazardous waste sites were compared, and correlation (r>0.97) was excellent between the two methods of analysis for each of the compounds most frequently detected: 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), 2,4-dinitrotoluene (2,4-DNT), 1,3-dinitrobenzene (1,3-DNB), 1,3,5-trinitrobenzene (TNB), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The analytes were extracted from soils with acetonitrile by 18 h of sonication in a cooled ultrasonic bath. Two soil-to-solvent ratios were evaluated: 2.00 g:10.00 ml and 25.0 g:50.0 ml. GC-ECD method detection limits were similar for the two soil-to-solvent ratios and were about 1 mug kg(-1) for the di- and trinitroaromatics, about 10 mug kg(-1) for the mono-nitroaromatics, 3 mug kg(-1) for RDX, 25 mug kg(-1) for HMX, and between 10 and 40 mug kg(-1) for the nitrate esters (nitroglycerine [NG] and pentaerythritol tetranitrate [PETN]). Spike recovery studies revealed artifacts introduced by the spiking procedure. Recoveries were low in some soils if the amount of soil spiked was large (25.0 g) compared to the volume of spike solution added (1.00 ml). Recoveries were close to 100% when 2.00-g soil samples were spiked with 1.00 ml of solution. Analytes most frequently found in soils collected near buried land mines were the microbial transformation products of TNT (2-amino-4,6-dinitrotoluene [2-Am-DNT] and 4-amino-2,6-dinitrotoluene [4-Am-DNT]), manufacturing impurities of TNT (2,4-DNT, 2,6-DNT, and 1,3-DNB), and TNT. The microbial reduction products of the isomers of DNT and of 1,3-DNB were also detected, but the ECD response to these compounds is poor.     

Residue level and dissipation pattern of lepimectin in shallots using high‐performance liquid chromatography coupled with photodiode array detection

Lepimectin, as an emulsifiable concentrate, was sprayed on shallots at the recommended dose rate (10 mL/20 L) to determine its residue levels, dissipation pattern, pre‐harvest residue limits (PHRLs), and health risk. Samples were randomly collected over 10 days, extracted with acetonitrile, purified using an amino solid‐phase extraction (NH₂‐SPE) cartridge and analyzed using a high‐performance liquid chromatography–photodiode array detection method. Field‐incurred samples were confirmed using ultra‐performance liquid chromatography–tandem mass spectrometry. The linearity was excellent, with a determination coefficient (R²) of ≥0.9991. The recoveries at two spiking levels (0.2 and 1.0 mg/kg) ranged from 84.49 to 87.64% with relative standard deviations of ≤7.04%. The developed method was applied to field samples grown in separate greenhouses, one located in Naju and one in Muan, in the Republic of Korea. The dissipation pattern was described by first‐order kinetics with half‐lives of 1.9 (Naju) and 1.7 days (Muan). The PHRL curves indicated that, if the lepimectin residues are <0.18 (Naju) and <0.13 mg/kg (Muan) 5 days before harvest, the residue levels will be lower than the maximum residue limit (0.05 mg/kg) upon harvesting. The risk assessment data indicated that lepimectin is safe for use in the cultivation of shallots, with no risk of detrimental effects to the consumer.     

Determination of methylmercury in biological samples by capillary gas chromatography with electron capture detection

A precise and accurate method has been developed for the determination of methylmercury in biological material using capillary gas chromatography with electron-capture detection. Homogenized fish or mussel samples were digested with acid, spiked with ethylmercury chloride as an internal standard and extracted with toluene. After treatment of the solvent extract with sodium thiosulphate and cupric bromide the alkylmercurials were extracted into benzene as their bromide derivatives and analyzed using an OV-275 coated glass capillary column. The detection limit of the method for methylmercury was 5 g/kg tissue.     

Derivatization and determination of arsenic in marine samples by gas chromatography with electron capture detection

Summary Arsenic in marine samples was determined by gas chromatography with electron capture detection after derivatization with 2,3-dimercaptopropanol. Biological tissues and sediments were analyzed after acid decomposition. For sea water, arsenic was preconcentrated by coprecipitation with hydrous iron (III) oxide. The results obtained by this approach compare favourably with the certified values of the reference materials analyzed. Presented at the 15th International Symposium on Chromatography, Nürnberg, October 1984     

Determination of polychlorinated biphenyls and organochlorine pesticides in human serum by gas chromatography with micro-electron capture detector

A method for determination of concentrations of polychlorinated biphenyl congeners (PCB-28, 52, 101, 118, 138, 153, 156, and 187) and organochlorine pesticides (hexachlorobenzene, alpha-hexachlorocyclohexane, beta-hexachlorocyclohexane, gamma-hexachlorocyclohexane, delta-hexachlorocyclohexane, p,p'-dichlorodiphenyl dichloroethylene, o,p'-dichlorodiphenyl trichloroethane, p,p'-dichlorodiphenyl dichloroethane, p,p'-dichlorodiphenyl trichloroethane, alpha-chlordane, gamma-chlordane, heptachlor, heptachlor epoxide, and aldrin) in human serum is developed. Recovery is assessed with artificial serum, in which PCBs and OCPs could not be detected. The method is then confirmed with pooled human serum. Experiments are performed by adding two concentrations of analytes (0.5 μg/L and 1.0 μg/L) to both matrices. The sample pretreatment process involves denaturing with a mixture of water-1-propanol (v:v, 85:15), extraction with a C-18 cartridge, and cleanup with an Alumina B cartridge. This process required about 2 mL of serum. The limit of detection ranged from 0.05-0.35 μg/L for all the analytes. Recovery of analytes at low and high spiking concentrations varied from 63-122% and 61-124% for artificial serum and pooled human serum, respectively. Relative standard deviation was lower than 16% and 18% for artificial serum and pooled human serum, respectively. Stability of the method, expressed as relative standard deviation, was lower than 14%. The method has been applied in epidemiological research.     

高效液相色谱法同时测定稻田中苄嘧磺隆和苯噻酰草胺残留

建立了同时测定稻田(稻田土壤、水和植株)中苄嘧磺隆和苯噻酰草胺残留量的高效液相色谱(HPLC)分析方法。稻田水样品用二氯甲烷直接萃取;稻田土壤样品用碱性乙腈-二氯甲烷(1:1, v/v)混合液直接提取;水稻植株样品用碱性二氯甲烷提取后,二氯甲烷提取液经弗罗里硅土柱净化。上述样品溶液采用C18不锈钢色谱柱(150 mm×4.6 mm, 5 μm)分离,流动相为水-甲醇(30:70, v/v),流速为0.5 mL/min,柱温为30 ℃,紫外检测波长为238 nm,外标法定量。苄嘧磺隆和苯噻酰草胺在0.05～5.00 mg/L范围内的线性关系均很好(r＞0.9999)。在稻田水、土壤和水稻植株中添加3个水平(0.05, 0.10, 1.00 mg/kg)的苄嘧磺隆和苯噻酰草胺,两者的回收率均在85.39%～113.33%之间,相对标准偏差为0.91%～10.24%。这表明该方法的灵敏度、准确度和精密度均符合农药残留测定的技术要求。     

Multiresidue determination of pyrethroid pesticide residues in pepper through a modified QuEChERS method and gas chromatography with electron capture detection

This study developed and used a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with gas chromatography with electron capture detection to determine eight pyrethroid pesticide residues in green, red and dehydrated red peppers. Pyrethroids were extracted with acetonitrile, partitioned with sodium chloride and purified with primary secondary amino and graphitized carbon black in hexane. The QuEChERS extraction conditions were optimized, and the matrix effects that might influence recoveries were evaluated and minimized using matrix‐matched calibration curves. Under the optimized conditions, the calibration curves for pyrethroid pesticides showed good linearities in the concentration range of 0.05–20 µg/mL with determination coefficients (R²) >0.997. The limits of quantification of eight pyrethroids were 0.004–0.04 mg/kg for green and red pepper and 0.04–0.5 mg/kg for dehydrated red pepper. These values are below the suggested regulatory maximum residue limits. The mean recoveries ranged between 79.0 and 104%, and the relative standard deviations were <11%. The developed method was successfully applied to commercial samples. Some samples were found to contain pyrethroid pesticides with levels below the legal limits. Copyright © 2015 John Wiley & Sons, Ltd.     

Simultaneous determination of florfenicol and florfenicol amine in fish, shrimp, and swine muscle by gas chromatography with a microcell electron capture detector

A rapid and sensitive gas chromatography method was developed for the simultaneous determination of florfenicol (FF) and its metabolite florfenicol amine (FFA) in fish, shrimp, and swine muscle. The extracted samples were defatted with hexane and cleaned up by solid-phase extraction using Oasis MCX cartridges. The eluate was evaporated to dryness, and residues were derivatized and determined by gas chromatography with a microcell electron capture detector. Overall average recoveries ranged from 81.7 to 109.7% for fish, 94.1 to 103.4% for shrimp, and 71.5 to 91.4% for swine muscle. The detection limit was 0.5 ng/g for FF and 1 ng/g for FFA, respectively. The method was validated for the determination of incurred swine muscle samples in an actual residue study.