固相萃取-气相色谱-质谱法测定鸡蛋中160种农药残留

建立了串联组合柱固相萃取-气相色谱-质谱法检测鸡蛋中160种农药多残留的分析方法。鸡蛋样品用乙腈均质和超声波提取,提取液采用C18和PSA串联组合柱净化,气相色谱-质谱仪(GC-MS)分析。GC-MS采用SIM模式,外标法定量。在优化过的条件下进行测试,本法检出限(S/N≥3)为0.01~0.05 mg/kg,在加标水平为0.05 mg/kg时,方法回收率为63.2%~126%,相对标准偏差为2.3%~13%。     

全自动固相萃取-凝胶净化-气相色谱-串联质谱检测耕地水渠中5种农药残留方法的建立

建立全自动固相萃取-凝胶净化-GC-MS/MS对耕地水渠中的5种农药残留（螺螨酯、肟菌酯、吡唑醚菌酯、2,4-滴丁酯和七氟菊酯）的检测方法。采用全自动固相萃取技术,选择ENVI-Carb固相萃取柱对耕地水样品进行农药提取。提取液经凝胶净化色谱净化后在氮吹仪中吹至近干。加入1 mL乙酸乙酯溶解残渣,0.22μm微孔滤膜过滤后进样气相色谱质谱联用仪（GC-MS/MS）以多反应监测模式（MRM）扫描,外标法定量。结果表明螺螨酯、肟菌酯、吡唑醚菌酯、2,4-滴丁酯和七氟菊酯在质量浓度0.01～2.0μg/mL范围内线性关系良好,线性相关系数均大于0.995,检出限如下：螺螨酯:4.23μg/L、肟菌酯:3.52μg/L、吡唑醚菌酯:3.69μg/L、2,4-滴丁酯:2.26μg/L、七氟菊酯：1.25μg/mL。样品在低、中、高三水平浓度点的回收率在90.9%～101.3%之间,精密度测定结果的相对标准偏差在1.68%～4.03%(n=6)。该方法净化效果好,定性定量结果准确,适用于水样中农药残留的监测。     

固相萃取净化-气相色谱-质谱法测定鳗鱼中多种农药残留量

建立了固相萃取-气相色谱串联质谱法检测鳗鱼中丁烯氟虫腈、三氯杀蟎醇等20种农药残留的分析方法。试样经乙腈提取后加入适量的去离子水和正己烷除去水溶性杂质和脂溶性杂质,再经填有中性氧化铝、C18和PSA混合填料的自组装固相萃取柱净化后进行GC-MS检测分析。采用选择离子扫描方式,用内标法进行定量。本方法简便、快速,方法的检出限(S/N=3)为0.001~0.009 mg/kg,在加标水平为0.01 mg/kg时,平均回收率为70.7~120%,相对标准偏差(RSD)为2.9~7.2%;在加标水平为0.02 mg/kg时,平均回收率为70.3~120%,相对标准偏差(RSD)为2.9~6.2%。     

用固相萃取-气相色谱质谱法检测金银花中有机氯农药方法研究

本文介绍了检测金银花中20种有机氯农药残留的方法.样品以丙酮-正己烷(v∶v=1∶4)混合溶剂提取,经弗罗里矽固相萃取净化与富集,采用毛细管柱气相色谱质谱进行检测与分析.本方法采取的线性范围0.01 mg/L ～ 0.4m g/L,加标平均回收率为80.2％ ～ 115.4％,最低检出限为0.01 mg/kg,建立了气...     

分散固相萃取-气相色谱-质谱法测定大豆油中102种农药残留量

建立了分散固相萃取-气相色谱-质谱法快速检测大豆油中102种农药残留的分析方法.样品用正己烷溶解,乙腈反萃取,C18和PSA粉末分散固相萃取净化后供气相色谱-质谱仪(GC-MS)分析.采用选择离子扫描方式,外标法定量.该方法简便、快速,通过优化前处理和上机条件,在最优条件下进行测试,方法的定量下限(S、N≥10)为0....     

固相萃取-液相色谱串联质谱法测定葡萄酒中27种农药残留

建立固相萃取-液相色谱串联质谱的分析方法同时检测葡萄酒中27种农药残留。葡萄酒样品经乙腈超声提取,进行40℃旋转蒸发后,使用CARB/PSA双层SPE小柱进行净化,采用C18色谱柱分离,以含甲酸的乙酸铵缓冲液和乙腈为流动相进行梯度洗脱,在质谱的正离子多反应监测(MRM)模式下进行检测。结果表明:该方法对空白葡萄酒加标水平下27种农药残留的测定线性良好,检测下限(10S/N)在2.5~10μg·kg-1之间,分别在不同3个浓度水平上用标准加入法进行回收试验,平均回收率在60~88%之间,相对标准偏差(n=6)在5.5到16.2%之间。该方法快速准确,灵敏度好,可满足葡萄酒产品的日常检测。     

固相萃取-气相色谱法测定葡萄酒中16种有机磷农药残留

利用固相萃取(SPE)/气相色谱火焰光度(GC-FPD)技术建立了葡萄酒中16种有机磷农药残留量分析方法。样品加水稀释,过HLB小柱和LC-NH2小柱净化,浓缩、定容后,用气相色谱测定,外标法定量。各农药的方法定量限(LOQ)均为为0.01 mg/kg。添加回收实验,16种有机磷农药添加浓度为0.01-0.10 mg/kg时,添加回收率为65.3-92.3%,变异系数≤10%。     

自动固相萃取与气相色谱--质谱联用测定水中有机磷农药

采用自动固相萃取法预处理,用气相色谱-质谱仪测定有机磷农药。最低检出限在0.10~0.30mg/L之间,水样加标回收率为75%~105%,样品经5次重复测定后相对标准偏差均小于6.0%。结果表明,该法具有简单、快速、准确的特点。     

固相微萃取-气相色谱-质谱法在烟草香味成分分析中的应用

采用固相微萃取-气相色谱-质谱(SPME—GC—MS)法定性分析烟叶和成品烟的挥发性香味成分，共鉴定了烟叶中的29种挥发性成分和成品烟中的20种挥发性成分。该方法简单、快速，适用于烟草样品的定性分析检测。     

镁铝铁层状金属氢氧化物固相萃取有机磷农药的研究

建立镁铝铁层状金属氢氧化物(Mg-Al-Fe-LDH)复合材料固相萃取气相色谱质谱法(GC-MS)测定水中的敌敌畏,乐果,氯吡硫磷,水胺硫磷的分析方法.复合材料用量为2 g,萃取12 min,二氯甲烷作为洗脱剂,洗脱剂用量为2 mL,洗脱时间1 min,4种农药的质量浓度在0.01～10 ng/mL范围内与峰面积线性关...     

Trace level determination of organophosphorus pesticides in water with the new direct-electron ionization LC/MS interface

A new LC/MS method for the determination of organophosphorus pesticides in water, based on the use of direct-electron ionization (EI) interface, is presented. Direct-EI is a new device that, in a very simple fashion, couples a nano-HPLC system with a mass spectrometer equipped with electron ionization capability. The nanoscale liquid flow allows for a direct introduction of eluate into the ion source and, after nebulization, for its ionization under typical EI conditions. Library-matchable EI spectra are generated for a choice of full scan or SIM detection of the analytes. In our case, a selection of organophosphorus pesticides, commonly distributed in local sugar beet cultivation, were considered. The new interface permits a very sensitive detection of the analytes in a wide range of linear response (0.09-9 ng). When applied to a real sample, the method allowed detecting four different pesticides at a concentration level of approximately 3 ng x L(-1).     

全自动在线HS-SPME-GC-MS/MS检测鱼塘投毒案件水样中的13种有机磷农药

建立全自动在线顶空固相微萃取-气相色谱串联质谱技术(HS-SPME-GC-MS/MS)检测鱼塘投毒案件水样中13种有机磷农药的方法.将2 mL水样中加入0.6 g氯化钠(NaCl)置于20 mL顶空瓶中,使用直径为100μm的聚二甲基硅氧烷(PDMS)萃取纤维,在75℃条件下萃取45 min,采用GC-MS/MS多反应...     

A LC/MS method for the determination of cyanobacteria toxins in water

The cyanobacteria toxins anatoxin-a, microcystin-LR, microcystin-RR, microcystin-YR, and nodularin were separated in less than 30 min on several 1 mm x 15 cm reversed-phase liquid chromatography (LC) columns, and their electrospray mass spectra were measured using injections of 50 ng or less with a benchtop time-of-flight (TOF) mass spectrometer. New data from this work include the following: (a) the impact of acetic acid concentrations in the methanol-water mobile phase on measured ion abundances; (b) the performance of the electrospray-TOF mass spectrometer as an LC detector; (c) the accuracy and precision of exact m/z measurements after LC separation with a routinely used mass spectrometer resolving power of 5000; and (d) recoveries of the five toxins from reagent water, river waters, and sewage treatment plant effluent samples extracted with C-18 silica particles enmeshed in thin Teflon membrane filter disks. This technique has the potential of providing a relatively simple and reasonable-cost sample preparation and LC/MS method that provides the sensitivity, selectivity, reliability, and information content needed for source and drinking water occurrence and human exposure studies.     

固相萃取-液相色谱-质谱法检测水产养殖水中的孔雀石绿及其代谢物、氧氟沙星、恩诺沙星和土霉素微量残留

研究创建固相萃取-液质色谱-质谱法检测水产养殖水中的孔雀石绿及其代谢物、氧氟沙星、恩诺沙星和土霉素微量残留的分析方法.随机在水产养殖厂采集水产养殖水样2 L,过滤以去除肉眼可见异物,加0.1 mol/L氢氧化钠或盐酸溶液,调节pH值至7.0,取预处理过的水样1 L置样品架上,以15 mL/min的流量,过固相萃取柱,最...     

LC/MS/MS method for quantitative determination of long-chain fatty acyl-CoAs

Long-chain acyl-CoA esters (LCACoAs) are activated lipid species that represent key substrates in lipid metabolism. The relationship between lipid metabolism disorders and type 2 diabetes has attracted much attention to this class of metabolites. This paper presents a highly sensitive and robust on-line LC/MS(2) procedure for quantitative determination of LCACoAs from rat liver. A fast SPE method has been developed without the need for time-consuming evaporation steps for sample preparation. LCACoAs were separated with high resolution using a C18 reversed-phase column at high pH (10.5) with an ammonium hydroxide and acetonitrile gradient. Five LCACoAs (C16:0, C16:1, C18:0 C18:1, C18:2) were quantified by selective multireaction monitoring using a triple quadrupole mass spectrometer in positive electrospray ionization mode. It is possible to perform a neutral loss scan of 507 for lipid profiling of complex LCACoA mixtures in tissue extracts. The method presented was validated according to ICH guidelines for quantitative determination of five LCACoAs for physiological concentrations in 100-200 mg of tissue with accuracies ranging from 94.8 to 110.8%, interrun precisions between 2.6 and 12.2%, and intrarun precisions between 1.2 and 4.4%. Due to the high sensitivity of the developed method, the amount of tissue biopsied for reliable quantification can be reduced. This may be advantageous in the quantification of LCACoAs in humans.     

SPE-GC/MS法测定水中有机磷和氨基甲酸酯农药

采用固相萃取(SPE)技术,对水样中20种有机磷类、氨基甲酸酯类农药进行提取、净化、浓缩前处理,优选了固相萃取小柱填料及萃取、净化条件.优化了气相色谱,质谱(GC/MS)仪器工作参数,建立了水样中20种农药的SPE-GC/MS分析方法.针对不同农药,本法回收率在90.83%～105.0%之间,测定精密度BSD在3.20%.12.52%之间.SCAN检测模式的检出限在0.0003mg/L～0.003mg/L之间,SIM检测模式的检出限在0.0002mg/L～0.0022mg/L之间.本法简便、快速、灵敏、可靠性强.     

超高效液相色谱质谱法测定水产品中恩诺沙星含量的不确定度评价

采用超高效液相色谱质谱法测定水产品中恩诺沙星的含量,分析不确定度的来源,建立评估的数学模型,通过计算不确定度的各主要分量,给出了测定结果的扩展不确定度.评定结果表明:影响检测结果不确定度的主要因素为标准溶液的配置、样品的回收率和测量重复性等.     

液相色谱-串级质谱联用法测定蜂王浆中氯霉素残留量

液相色谱-串级质谱联用仪作为一种新兴的色质联用技术,具有极高的灵敏度,现广泛应用于动物源性食品中痕量氯霉素的定性与定量测定。该文采用液相色谱一串级质谱联用法不需要使用内标,而直接对蜂王浆中低于ppb级的氯霉素残留进行定性定量分析。蜂王浆样品在（0．1～2）μg/l水平上回收率达到80％～90％,重现性良好。     

Microwave accelerated selective Soxhlet extraction for the determination of organophosphorus and carbamate pesticides in ginseng with gas chromatography/mass spectrometry

Microwave accelerated selective Soxhlet extraction (MA-SSE), a novel selective extraction technique, was investigated in this study. A Soxhlet extraction system containing a glass filter was designed as an extractor. During the procedure of MA-SSE, both the target analytes and the interfering components were extracted from the sample into the extraction solvent enhanced by microwave irradiation. After the solvent flowed though the sorbent, the interfering components were adsorbed by the sorbent, and the target analytes remaining in the solvent were collected in the extraction bottle. No cleanup or filtration was required after extraction. The efficiency of the MA-SSE approach was demonstrated in the determination of organophosphorus and carbamate pesticide residues in ginseng by gas chromatography/mass spectrometry (GC/MS). Under the optimized conditions, low limits of detection (0.050-0.50 μg/kg) were obtained. The recoveries were in the range of 72.0-110.1% with relative standard deviations less than 7.1%. Because of the effect of microwave irradiation, MA-SSE showed significant advantage compared with other extraction techniques. The sorbent used in this study showed good cleanup ability. The mechanism of MA-SSE was demonstrated to be based on the rupture of the cell walls according to the structural changes of ginseng samples. On the basis of the results, MA-SSE as a simple and effective sample preparation technique for the analysis of pesticide residues in complex matrixes shows great promise.     

Chlorination of organophosphorus pesticides in natural waters

Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 degrees C and pH 7 were determined to be 110.9, 0.004 and 191.6 M(-1) s(-1) for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L(-1) was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety.