气相色谱-电子轰击电离/正化学电离质谱法测定白菜和苹果中3种有机锡类农药残留

分别采用电子轰击电离(EI)源和正化学电离(PCI)源两种离子源技术建立了气相色谱-质谱(GC-MS)同时测定白菜和苹果中苯丁锡、三苯锡和三环锡含量的方法,并对这两种方法进行了比较。样品经氢溴酸消解、丙酮-正己烷(1∶2,v/v)提取,四乙基硼化钠衍生后用Florisil固相萃取柱净化,分别在EI源和PCI源下以选择离子监测模式进行测定。结果表明,方法的检出限(S/N=3)分别为0.01~0.05 mg/kg(EI源)和0.01~0.02 mg/kg(PCI源),定量限(S/N=10)分别为0.03~0.16 mg/kg(EI源)和0.02~0.06 mg/kg(PCI源)。三苯锡、三环锡和苯丁锡分别在各自的线性范围内线性关系良好,相关系数(r~2)≥0.997。在50、100、200μg/kg 3个添加水平下,采用GC-EI/MS和GC-PCI/MS时,阴性样品中3种有机锡的平均回收率分别为59.24%~97.36%(苹果)、50.54%~94.54%(白菜)和65.38%~95.86%(苹果)、62.56%~90.44%(白菜),相对标准偏差(RSD)均不超过6.9%(n=6)。该方法简单、灵敏,PCI源的选择性优于EI源,两种方法可以相互结合提高检测结果的可靠性。     

阳离子固相萃取-超高效液相色谱-串联质谱法测定皮革制品中的4种三取代有机锡化合物

建立了超高效液相色谱-串联质谱测定皮革制品中三丁基锡、三苯基锡、双-三苯基锡氧化物、三环锡等4种三取代有机锡化合物(TOT)的方法。采用盐酸溶液提取皮革制品中的有机锡化合物,使其呈阳离子态,经阳离子固相萃取净化,有机锡化合物在超高效C18色谱柱中完成分离,在正离子模式下采用多反应监测模式进行串联质谱测定。三丁基锡、三苯基锡、双-三苯基锡氧化物(以三苯基锡计)的定量限为10 μg/kg,三环锡的定量限为20 μg/kg;分别添加4种待测物于空白皮革样品中,加标回收率为54.1%～101.4%,相对标准偏差为4.3%～9.8%。实验结果表明,该方法简单、灵敏、准确,各项技术指标均满足国内外法规的要求,可用于皮革制品中4种三取代有机锡化合物残留的确证检测。     

液相色谱-串联质谱法测定花粉中的链霉素和双氢链霉素

建立了花粉中链霉素（streptomycin,STR）与双氢链霉素（dihydrostreptomycin,DHS）的高效液相色谱-串联质谱（HPLC-MS/MS）检测方法。样品经提取液提取、三氯甲烷沉淀蛋白后,用C18固相萃取柱进行富集净化,采用HPLC-MS/MS对目标物进行定性确证和定量分析。在Protemix WCX-NP5色谱柱（100 mm×2.1 mm,5 μm）上以5%（v/v）甲酸、20 mmol/L醋酸铵和甲醇为流动相进行梯度洗脱分离;质谱采集模式为电喷雾正离子监测模式。链霉素和双氢链霉素的检出限（以信噪比（S/N）=3计）均为5 μg/kg,定量限（以S/N=10计）均为10 μg/kg;在10~200 μg/L的质量浓度范围内呈现良好的线性关系,相关系数（r）大于0.99。本底空白的松花粉、玉米花粉、茶花粉、葵花粉、油菜花粉、杂花粉等6种基质中10、20、50 μg/kg添加水平下的加标回收率范围为76.8%~100.3%,精密度范围为3.70%~12.6%。该方法无需使用对LC-MS联用仪容易造成污染的七氟正丁酸,且方法准确可靠,适用于大部分花粉基质的测定。     

正化学源-气相色谱-质谱法测定食用植物油中有机锡化合物残留

建立了正化学源-气相色谱-质谱技术测定食用植物油中有机锡化合物残留的方法。食用油样品经环己烷-乙酸乙酯（1：1，v/v）溶解后，经凝胶渗透色谱（GPC）净化，目标馏分用四乙基硼酸钠进行衍生。采用基质校正曲线外标法定量，在20~2000 μg/L范围内，7种有机锡化合物均呈现良好的线性关系，相关系数大于0.99，定量限为0.3~1.2 μg/kg。对芝麻油样品进行加标回收试验，在0.05、0.10、0.20 mg/kg 3个添加水平下，7种有机锡化合物的平均回收率为66.2%~103.2%，相对标准偏差均小于11.5%。该方法精密度好，灵敏度高，可用于食用植物油中有机锡化合物残留量的测定。     

气相色谱-质谱法测定玩具中单甲基锡迁移量及其假阳性的确证方法

基于欧盟玩具安全标准EN 71-3∶2013/A2∶2017中胃液迁移程序,建立了测定玩具中单甲基锡迁移量的气相色谱-质谱法（GC-MS）,并首次针对由此引起的单甲基锡假阳性问题建立了确证方法。经优化迁移条件、衍生步骤及色谱条件,单甲基锡在0.02~1.0 mg/L范围内呈现良好线性关系,相关系数（R²）为0.9992,方法检出限和定量限分别为0.11 mg/kg和0.32 mg/kg。单甲基锡在不同加标水平（0.1、0.5和1.5 μg）下的回收率为86.2%~104.2%,相对标准偏差为3.1%~8.2%（n=6）。实际样品测定表明,马口铁（锡铁合金）材质玩具表面涂层中检出了单甲基锡,迁移量为0.44~0.67 mg/kg,并以甲醇和丙酮为迁移溶剂对结果进行确证,经证实其为假阳性结果。     

快速溶剂萃取-气相色谱-串联质谱法同时测定土壤中有机氯及有机磷农药

建立了快速溶剂萃取（ASE）-气相色谱-串联质谱（GC-MS/MS）同时分析土壤中8种有机氯农药（OCPs）和5种有机磷农药（OPPs）的方法。样品由正己烷-丙酮（1：1,v/v）溶液萃取,经无水硫酸钠脱水、氮吹仪浓缩后,采用硅胶（Si）固相萃取小柱进行净化,正己烷-丙酮（1：1,v/v）溶液进行洗脱,然后经HP-5MS色谱柱（30 m×0.25 mm×0.25 μm）分离,在电子轰击电离源下以多反应监测（MRM）模式进行检测,内标法定量。分析结果表明,13种目标物在1.00~100 μg/L范围内线性关系良好,相关系数（R）大于0.995;加标回收率为66.8%~88.4%,能够实现准确定量;日内精密度与日间精密度均小于10%。当取样量为10.0 g时,8种OCPs的方法检出限为0.02~0.04 μg/kg,5种OPPs的方法检出限为0.06~0.12 μg/kg,能够满足土壤农药残留的检测要求。     

两种离子化技术气相色谱-串联质谱法测定青菜与草莓中3种有机锡类农药残留

采用电子轰击(EI)和正化学(PCI)两种电离源技术,建立了气相色谱-串联质谱(GC-MS/MS)同时测定青菜和草莓中三环锡、三苯锡、苯丁锡农药残留的分析方法。样品经氢溴酸消解,丙酮-正己烷提取,经衍生后由Florisil固相萃取柱净化,分别采用EI和PCI两种电离源进行选择反应监测模式测定,采用基质匹配外标法定量。结果显示,在0.05~1.0 mg/L质量浓度范围内,3种有机锡农药呈良好线性,相关系数均大于0.998。两种方法中目标物的定量下限分别为0.019~0.042 mg/kg和0.009~0.042 mg/kg,均能满足国内外的限量要求。在0.05、0.10、0.20 mg/kg加标水平下,目标物的平均回收率为70.1%~93.9%,相对标准偏差(RSD)均小于10%。两种方法线性均较好,灵敏度较高,可用于水果蔬菜中有机锡农药的测定,且两种方法可实现互补,有助于提高定性和定量的可靠性。     

高效液相色谱-串联质谱法测定荔枝花粉和花蜜中腈菌唑和苯醚甲环唑残留

采用改良的QuEChERS-高效液相色谱-串联质谱（HPLC-MS/MS）技术,建立了荔枝花粉和花蜜中2种主要杀菌剂腈菌唑和苯醚甲环唑的测定方法。花粉和花蜜样品均由乙腈提取,花粉样品经0.9 g无水硫酸镁、0.15 g N-丙基乙二胺（PSA）和0.15 g十八烷基键合硅胶（C₁₈）吸附剂净化,花蜜样品由0.9 g无水硫酸镁和0.15 g PSA净化。采用Poroshell-120 EC-C₁₈色谱柱分离,以0.1%（v/v）甲酸水溶液-乙腈（25∶75,v/v）为流动相等度洗脱,在电喷雾离子（ESI）源、正离子扫描和选择离子监测模式下进行检测,基质匹配标准溶液法定量。结果显示：腈菌唑和苯醚甲环唑在1~100 μg/L范围内线性关系良好,相关系数（r²）均大于0.9990;腈菌唑和苯醚甲环唑的检出限（LOD）分别为0.25 μg/kg和0.50 μg/kg,定量限（LOQ）分别为0.83 μg/kg和1.7 μg/kg;腈菌唑和苯醚甲环唑在荔枝花粉和花蜜样品中的平均加标回收率分别为87.0%~95.2%和90.1%~96.4%,相对标准偏差（RSD）分别为1.2%~3.6%和0.7%~4.1%。该法快速、简便、灵敏,可用于荔枝花粉和花蜜样品中腈菌唑和苯醚甲环唑的痕量测定,可为蜜蜂等授粉昆虫的暴露性风险评估提供技术支持。     

乙基化衍生-气相色谱-串联质谱法测定葡萄酒中3种丁基锡:液液萃取和固相微萃取的比较

建立了葡萄酒中一丁基锡、二丁基锡和三丁基锡检测的两种分析方法,分别采用液液萃取法(LLE)和固相微萃取法(SPME),以四乙基硼化钠为衍生试剂,气相色谱-串联质谱(GC-MS/MS)检测,内标法定量。对两种方法的萃取条件(萃取时间、温度等)、衍生条件(pH、衍生试剂用量等)和GC-MS/MS条件进行了选择和优化。考察和对比了两种方法的灵敏度和准确度。结果表明,LLE和SPM E法的检出限分别为0.5μg/kg(以Sn计,下同)和0.01μg/kg,针对干红、干白和桃红3种葡萄酒基质,在4个添加水平下的回收率范围分别为70.7%~103.3%和61.7%~114.1%,RSD范围分别为2.2%~8.4%和6.6%~16.0%。LLE法稳定性好,方法准确可靠;SPM E法虽精密度稍差,但具有极高的灵敏度,而且操作简便,不需消耗有机溶剂。两种方法联合使用具有较宽的检测范围,适用于葡萄酒中丁基锡化合物的检测。     

超高效液相色谱-串联质谱法同时测定保健食品中丙磺舒、别嘌醇和苯溴马隆

建立了基于QuEChERS前处理的超高效液相色谱-串联质谱（UPLC-MS/MS）同时测定抗痛风类保健食品中别嘌醇、丙磺舒和苯溴马隆3种药物的检测方法。样品经含0.1%（v/v）氨水的乙腈溶液超声提取后，采用乙二胺-N-丙基硅烷（PSA）和十八烷基键合硅胶（C₁₈）吸附剂净化，用C₁₈色谱柱进行分离，0.1%（v/v）甲酸水溶液和甲醇为流动相进行梯度洗脱，采用电喷雾电离源、正负离子切换模式和多反应监测（MRM）模式检测。结果表明，别嘌醇、丙磺舒和苯溴马隆的检出限分别为5、25和25 μg/kg，定量限分别为17、80和80 μg/kg。抗痛风类保健食品中3种药物的平均加标回收率为76.8%~116.6%，相对标准偏差（RSD）为2.7%~14.6%。应用该法对68批次保健食品进行分析，其中1批次样品检出别嘌醇药物。该法操作简单，灵敏度高，可用于抗痛风类保健食品中别嘌醇、丙磺舒和苯溴马隆的测定。     

气相色谱-三重四极杆串联质谱法快速测定蔬菜水果中129种农药的残留量

采用QuEChERS方法结合气相色谱-串联质谱法(GC-MS/MS)建立了蔬菜、水果中129种农药残留同时检测的分析方法。试样用1%乙酸乙腈均质提取,采用混合型固相分散萃取剂净化后,用GC-MS/MS在多反应离子监测(MRM)模式下进行检测,外标法定量。结果表明,129种药物在一定的含量范围内线性关系良好,相关系数(r2)均大于0.98;不同基质在10 μg/kg添加水平下大部分农药的平均回收率为66.2%～124.7%,相对标准偏差(RSD)为0.9%～24.4%;方法的定量限(LOQ)为0.03～16.7 μg/kg。结果表明,该方法简便快速、灵敏可靠、经济有效,适用于蔬菜、水果中农药多残留的同时快速筛查测定。     

Comparison of GC/MSD and GC/AED for the determination of organotin compounds in the environment

Summary Methods are described for the analysis of environmental samples like water, sediment and suspended matter for the determination of all organotin compounds (OTs) that are currently used as biocides: tributyltin (TBT), triphenyltin (TPT), tricyclohexyltin (TCT) and fenbutatin oxide (FBTO). In water also five degradation products (di and mono substituted analogs) can be determined. Alkylation using a Grignard reagent was used to obtain OT derivatives amenable to gas chromatography (GC). Both methylation and pentylation have been employed for derivatization prior to GC analysis. The present results show that derivatization efficiencies for TPT, TCT and FBTO at trace levels are higher using methylation than pentylation. Detection limits for each type of sample matrix were determined using GC/Mass Selective Detection (GC/MSD) and GC/Atomic Emission Detection (AED). In sediment and suspended matter only tri-substituted OTs (i.e. the parent compounds) could be determined. Detection limits ranged from 0.2 to 10 ng/g dry weight. FBTO, not previously detected in environmental samples, was found at levels of 4 and 11 ng/g in a suspended matter sample and a sediment sample, respectively. In water the OTs and their degradation products were determined at levels of 1–10 ng/l (as tin) using 200 ml water samples.     

Automated headspace-solid-phase micro extraction-retention time locked-isotope dilution gas chromatography-mass spectrometry for the analysis of organotin compounds in water and sediment samples

An automated method for the simultaneous determination of six important organotin compounds namely monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TPhT) in water and sediment samples is described. The method is based on derivatization with sodium tetraethylborate followed by automated headspace-solid-phase micro extraction (SPME) combined with GC-MS under retention time locked (RTL) conditions. Home-synthesized deuterated organotin analogues were used as internal standards. Two high abundant fragment ions corresponding to the main tin isotopes Sn118 and Sn120 were chosen; one for quantification and one as qualifier ion. The method was validated and excellent figures of merit were obtained. Limits of quantification (LOQs) are from 1.3 to 15 ng l(-1) (ppt) for water samples and from 1.0 to 6.3 microg kg(-1) (ppb) for sediment samples. Accuracy for sediment samples was tested on spiked real-life sediment samples and on a reference PACS-2 marine harbor sediment. The developed method was used in a case-study at the harbor of Antwerp where sediment samples in different areas were taken and subsequently screened for TBT contamination. Concentrations ranged from 15 microg kg(-1) in the port of Antwerp up to 43 mg kg(-1) near a ship repair unit.     

Speciation of organotin compounds in marine sediments by capillary column gas chromatography-atomic absorption spectrometry coupled with hydride generation

A method for speciation of organotin compounds in marine sediments by solvent extraction combined with hydride generation gas chromatography-atomic absorption spectrometry has been developed. Sediment samples spiked with tributyltin and triphenyltin chlorides were homogenized in hydrochloric acid. The chlorides were extracted twice into toluene. Recoveries of the organotin compounds from the spiked sediment samples were improved by the addition of 8-quinolinol. Tributyltin and triphenyltin chlorides form ion-associates with 8-quinolinol in aqueous hydrochloric acid. The method was optimized with respect to derivatization reactions and extraction conditions. Interferences from Sn(II/IV) and additional 13 ions were investigated. Recoveries of 84-100% for tributyltin and 86-100% for triphenyltin were achieved using this method. The detection limits obtained for tributyltin and triphenyltin chlorides were 95 and 145 pg, respectively, corresponding to a relative detection limit of 95 and 145 ng kg(-1) in the sediment.     

Analysis of organotin compounds by grignard derivatization and gas chromatography-ion trap tandem mass spectrometry

The determination of organotin compounds in water using gas chromatography-tandem mass spectrometry (GC-MS-MS) is described. Several organotin derivatives were synthesized by the reaction of organotin chlorides with Grignard reagents such as methyl-, propyl- and pentylmagnesium halides. After the optimization of the GC-MS-MS conditions, several derivatizations with the Grignard reagents were compared by evaluating the molar responses and volatilities of the derivatives and derivatization yields. As a result, the derivatizing reagent of choice is pentylmagnesium bromide. Calibration curves for the mono-, di- and tributyltins and mono-, di- and triphenyltins with pentylmagnesium bromide were linear in the range of 0.5-100 pg of Sn. The instrumental detection limits of six organotins ranged from 0.20 to 0.35 pg of Sn. The recovery tests from water samples (500 ml) were performed by using sodium diethyldithiocarbamate (DDTC) as a complexing reagent. Except for monophenyltin, the absolute recoveries of organotins from pure water at 200 ng of Sn/l were satisfactory. The recoveries calibrated by surrogate compounds (perdeuterated organotin chlorides) ranged from 71 to 109%. The method detection limits ranged from 0.26 to 0.84 pg of Sn (500-ml sample). This method was applied to the recovery of organotins from river water and seawater. The calibrated recoveries were between 90 and 122%.     

Preparation of pentylated organotin standards for use in trace analysis with gas chromatography

A method for the preparation and purification of pentylated derivatives is described for nine organotin compounds that are relevant in environmental analysis (tributyltin acetate, dibutyltin dichloride, butyltin trichloride, triphenyltin chloride, diphenyltin dichloride, phenyltin trichloride, tricyclohexyltin hydroxide (cyhexatin), dicyclohexyltin dibromide and bis (trineophyltin) oxide (fenbutatinoxide)). The compounds are synthesized on a 100 mg scale and purified by column chromatography. Purity checks were performed with gas chromatography with mass selective detection. The mass spectrum of pentyltrineophyltin is presented.     

Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the determination of 148 pesticides in fruits and vegetables

This paper presented the applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in fruits and vegetables. Pesticides were extracted from fruits and vegetables using a buffered QuEChERS method. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 μg/kg. The method performance parameters including overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. For LC/ESI-MS/MS, 95% of the pesticides had recoveries between 81% and 110%; 97% had an intermediate precision ≤20%; and 95% (in fruits) or 93% (in vegetables) showed measurement uncertainty ≤40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. About 93% (in fruits) or 94% (in vegetables) of the pesticides had recoveries between 81% and 110%; 86% (in fruits) or 90% (in vegetables) had an intermediate precision ≤20%; and 79% (in fruits) or 88% (in vegetables) showed measurement uncertainty ≤40%. LC/ESI-MS/MS proved to be the first choice for quantification or pre-target analysis due to its superior sensitivity and good repeatability. UHPLC QqTOF MS provided accurate mass measurement and isotopic patterns, and was an ideal tool for post-target screening and confirmation.     

固相萃取-三重串联四极杆气相色谱/质谱联用分析蔬菜中43种农药残留留

建立了气相色谱/三重四极杆串联质谱同时分析蔬菜中43种农药残留的方法。采用乙腈提取样品中待测组分,经固相萃取法(SPE)净化后采用气相色谱/三重四极杆串联质谱在多反应监测(MRM)模式下进行外标法定量测定。分别对青菜进行3个水平(10、80、200 μg/kg)的加标回收试验,其回收率为62.2%～170.0%,其中36种农药的回收率为70.0%～120.0%。方法的相对标准偏差(RSD)小于18%,定量限(LOQ)为0.3～4.4 μg/kg。该分析方法背景干扰低,灵敏度高,适合蔬菜中多种农药及杀虫剂残留的测定。