气相色谱/质谱法测定鱼塘中的痕量硫丹

利用气相色谱/质谱(GC/MS),测定了鱼塘中痕量的硫丹,同时实现了硫丹的定性、定量.样品提取简便、高效,无需净化.用GC/MS的选择离子记录(SIR)方式测定低浓度硫丹的含量.硫丹在0.2～1000.0μg/mL范围内呈线性,该方法的检出限为0.086μg/mL,标准添加1.0、50μg/mL硫丹的回收率为87%、92%,测定的相对标准偏差为6.2%、13.1%.本方法能够满足痕量分析的实际要求.     

改进QuChERS–气相色谱法测定水产品中硫丹残留量

建立了水产品中硫丹残留量的改进样品快速处理技术(QuChERS)–气相色谱法检测方法。水产品样品以乙腈为提取剂,应用改进的QuChERS方法进行净化,并利用气相色谱法进行检测,以基质匹配标准溶液外标法定量。在2~10μg/kg添加水平范围内,α-硫丹和β-硫丹的平均回收率分别为97.8%~107.7%,98.5%~102.9%;测定结果的相对标准偏差分别为1.77%~10.4%,2.55%~5.84%;方法检出限分别为1.8,2.0μg/kg;定量限分别为5.4,6.0μg/kg。该法满足水产品中硫丹残留量的测定要求。     

气相色谱-负离子化学电离质谱法测定水产品中残留的硫丹及其代谢物

建立了水产品中α-硫丹、β-硫丹及硫丹硫酸酯残留量的分析方法。样品经丙酮-正己烷混合溶剂提取、转溶至乙腈中、冷冻去除油脂、活性炭和中性氧化铝固相萃取小柱(SPE)串联净化处理后,以选择离子方式进行气相色谱-负离子化学电离质谱分析,采用外标法定量。硫丹和硫丹硫酸酯的选择离子分别为m/z 406,408,404,372和m/z 386,388,384,422。每种化合物的最低定量检测限为0.5 μg/kg,回收率为83%～105%,相对标准偏差低于13%。该方法简单、快速、准确,能满足水产品中硫丹残留的检测需要。     

气相色谱-质谱法测定茶叶中的25种有机氯农药残留

利用气相色谱-质谱(GC-MS)联用技术建立了茶叶中25种有机氯农药残留同时测定的方法。茶叶样品中有机氯农药残留通过正己烷-丙酮(体积比为2∶1)溶液提取,浓缩后过弗罗里硅土柱净化,采用正己烷-乙酸乙酯(体积比为9∶1)溶液淋洗,GC-MS选择离子监测模式(SIM)检测。方法的线性范围为0.010～0.500 mg/L。在茶叶样品中0.01～0.20 mg/kg加标水平下有机氯混标的加标回收率为70.8%～105.5%,相对标准偏差为1.6%～12.7%。除硫丹Ⅰ和硫丹Ⅱ的定量限为0.02 mg/kg以外,其余23种有机氯农药的定量限均为0.01 mg/kg。     

毛细管气相色谱法测定南美白对虾中硫丹的残留量

建立了运用毛细管气相色谱检测南美白对虾中硫丹残留的快速测定方法。用乙酸乙酯提取样品中的硫丹,提取液浓缩后以中性氧化铝和活性炭小柱进行双级柱色谱净化,用正己烷-乙酸乙酯(体积比为1∶1)洗脱,洗脱液用气相色谱-电子捕获检测器检测,以保留时间定性,外标法定量。在南美白对虾样品中分别添加0.20,0.10,0.04和0.02 mg/kg硫丹标准品,测得添加回收率为80.5%～109.5%,相对标准偏差为3.6%～8.4%。该方法在不具备凝胶渗透色谱条件下也能进行硫丹残留的检测,具有简便、准确的特点,能满足常规检测及食品安全监控的需要。     

溶剂萃取-气相色谱法测定粮食中硫丹类农药残留量

提出了粮食中α-硫丹、β-硫丹、硫丹乙酯、硫丹丙酯和硫丹硫酸盐5种硫丹类有机氯农药的气相色谱测定方法。样品粉碎后以丙酮为溶剂经快速溶剂萃取仪在加热(80℃)状态下静态提取5min、氟罗里硅土固相萃取柱净化后注入毛细管气相色谱仪分离测定。5种硫丹类农药的测定下限(10S/N)分别为0.82～1.75μg.kg-1,平均回收率为88.9%～99.1%,相对标准偏差(n=5)为6.80%～10.23%。     

全自动在线顶空固相微萃取-气相色谱-串联质谱法测定鱼塘投毒案件水样中硫丹和硫丹硫酸酯

鱼塘水样采用全自动在线顶空固相微萃取进行萃取:萃取温度为75℃;萃取时间为60min;氯化钠加入量为0.3kg·L~(-1);样品体积为2.0mL。采用气相色谱-串联质谱法测定水样中硫丹(α-硫丹、β-硫丹)和硫丹硫酸酯的含量,在气相色谱分离中采用DB-5ms毛细管色谱柱,在串联质谱分析中采用多反应监测模式。α-硫丹、β-硫丹和硫丹硫酸酯的质量浓度在一定范围内与其对应的峰面积呈线性关系,检出限(3S/N)为0.001～0.015μg·L~(-1),测定下限(10S/N)为0.003～0.050μg·L~(-1)。以空白水样为基体进行加标回收试验,所得回收率为83.6%～117%,测定值的日内相对标准偏差(n=6)为2.2%～18%,日间相对标准偏差(n=3)为4.2%～18%。     

超声波提取-气相色谱-质谱联用法测定苏丹红Ⅰ残留量

研究了苏丹红Ⅰ的气-质联用检测方法。样品中的苏丹红Ⅰ用超声波提取,采用选择离子(SIM)方式,据保留时间和特征离子丰度比对其进行确证。此方法可以在13 min之内定性和定量地快速检测苏丹红Ⅰ残留,通过多次试验验证,添加量为0.01~1.00μg,回收率在82%~97%之间,相对标准偏差小于5%,检出限为6.0×10-4μg/g。     

QuEChERS/GC-MS法测定水产品中的硫丹及其代谢物

建立了QuEChERS法提取净化、气相色谱质谱联用仪测定水产品中的硫丹(α-硫丹和β-硫丹)及其代谢物硫丹硫酸盐的方法。样品用10 mL乙腈提取,取1 mL加入PSA和C18粉末振荡后离心,上清液过滤膜后用气相色谱质谱联用仪测定。3种物质在0.5~100μg/L范围内线性良好,在1,5,10μg/kg3个浓度水平下3种目标物平均添加回收率在72.3%~101.6%之间,RSD小于10%,定量限为0.5μg/kg,满足进出口检测要求,已应用于水产品中硫丹残留的测定。     

全自动固相萃取-高效液相色谱-串联质谱法测定食糖中的雌二醇

建立了全自动固相萃取-高效液相色谱-串联质谱检测食糖中雌二醇含量的方法。食糖样品经水溶解后,用碱化乙腈提取,经HLB固相萃取柱净化,采用高效液相色谱-串联质谱分析,内标法定量。质谱分析采用电喷雾电离(ESI)负离子扫描,多反应监测(MRM)模式。雌二醇定量离子对为271.1/144.8和271.1/183.2,内标D2-雌二醇定量离子对为273.2/147.0。实验表明,经SPE柱净化后基质效应明显降低,样品中添加0.5~10 μg/kg的雌二醇,其回收率为83.9%~95.1%,相对标准偏差(n=6)小于10%。雌二醇的检出限为0.1 μg/kg,定量限为0.5 μg/kg。该方法提取效果好,具有良好的灵敏度、回收率和重复性。     

Simultaneous determination of methylmercury and ethylmercury in rice by capillary gas chromatography coupled on-line with atomic fluorescence spectrometry

A comprehensive method for simultaneous determination of methylmercury (MeHg) and ethylmercury (EtHg) in rice by capillary gas chromatography (GC) coupled on-line with atomic fluorescence spectrometry was developed. The experimental conditions, including the pyrolyzer temperature and flow rates of the make-up gas and sheath gas, were optimized in detail. The absolute detection limits (3sigma) were 0.005 ng as Hg for both MeHg and EtHg. The relative standard deviation values (n=5) for 10 ng Hg/mL of MeHg and EtHg were 2.5 and 1.3%, respectively. The method was evaluated by analyzing 2 certified reference materials (DORM-2 and GBW08508), and the determined values of MeHg and total mercury concentrations were in good agreement with the certified values. In addition, the recoveries of MeHg and EtHg spiked into a rice sample collected from Jiangsu province in China were 86 and 77%, respectively. The proposed method was applied to analysis of MeHg and EtHg in 25 rice samples cultivated in 15 provinces of China. In all samples, MeHg was detectable and no EtHg was found. The MeHg contents in rice samples ranged from 1.9 to 10.5 ng/g, accounting for 7-44% of the total mercury measured.     

Determination of endosulfan isomers and endosulfan sulfate in tomato juice by matrix solid-phase dispersion and gas chromatography

A rapid method based on matrix solid-phase dispersion was developed for the determination of endosulfan isomers and endosulfan sulfate in commercial tomato juice. After the optimisation of different parameters such as the type of adsorbent, the extraction solvent, and the extraction assistance by sonication, the recoveries obtained ranged from 81 to 100% with relative standard deviations equal to or lower than 10%. The analysis of samples was accomplished using gas chromatography with electron-capture detection and the identity of endosulfan residues was confirmed by gas chromatography-mass spectrometry with selected ion monitoring. The detection limit for these compounds, calculated as three times the background noise, was 1 microg/kg. The proposed method was applied to the analysis of these compounds in commercial juice samples and levels of endosulfan between 1 and 5 microg/kg were detected in some samples.     

化妆品中24种过敏原的气相色谱-质谱法测定

建立了气相色谱-质谱(GC-MS)法同时测定化妆品中24种过敏原的分析方法。样品经甲醇超声提取,以选择离子模式(SIM)进行定性及定量分析。24种过敏原在质量浓度0.2～100 mg/L范围内呈良好的线性关系,相关系数r2﹥0.995,检出限为2～10 mg/kg,平均回收率为80%～104%,相对标准偏差为1.8%～9.3%。该方法快速、准确、灵敏度高。通过对77名患者使用的150份可疑致敏化妆品测试发现,24种过敏物质的阳性检出率为78%,其中至少有1种过敏物质含量大于10 mg/kg的样本占阳性样本的81.2%。71名过敏患者(92.2%)使用的化妆品中检出致敏物;其中至少有一种过敏物质的检出值大于10 mg/kg的占90.1%。结果显示,24种过敏物质是化妆品接触性皮炎的主要致敏原。     

固相萃取-气相色谱法测定茶叶中残留的92种农药

建立了茶叶中92种农药多残留的气相色谱分析方法。茶叶样品用乙腈一次性提取后,有机磷类农药经Envi-Carb固相小柱净化,用10 mL乙腈-甲苯(体积比为3∶1)洗脱剂淋洗,气相色谱-火焰光度检测器(GC-FPD)检测;有机氯类和拟除虫菊酯类农药经串联Envi-Carb和NH2固相小柱净化,用5 mL乙腈-甲苯(体积比为3∶1)洗脱剂淋洗,GC-电子捕获检测器(ECD)检测。采用外标法定量。添加回收试验的结果表明:92种农药的平均回收率为80.3%～117.1%,相对标准偏差为1.5%～9.8%。方法的检出限为0.0025～0.10 mg/kg。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。     

Development and validation of a gas chromatographic method for analysis of fosfomycin in chicken muscle samples

Summary A gas chromatographic method for the determination of residues of Fosfomycin in chicken muscle samples has been developed. Muscle samples were homogenised with TRIS buffer, containing phenylphosphonic acid (as internal standard) and Fosfomycin using a tissue homogenizer. Afterwards, the samples were ultrafiltered and the ultrafiltrate was evaporated to dryness. A silylation reagent for derivatization was used in order to reconstitute the residue. The linear concentration range of application was 10–150 μgg⁻¹, with a detection and quantitation limit of 3.11 and 10 μgg⁻¹, respectively. The method was efficient with a mean recovery of 87.83% from spiked muscle. The results obtained show that gas chromatography is a useful method for the determination of Fosfomycin residues in chicken muscle samples.     

气相色谱法测定电子烟烟液及气溶胶中双乙酰和乙酰丙酰

建立气相色谱法氢火焰离子化检测器测定电子烟烟液和气溶胶中双乙酰和乙酰丙酰含量的方法。样品以20 mL乙醇为萃取剂,涡旋振荡萃取10 min,采用气相色谱外标法进行定量分析。双乙酰和乙酰丙酰质量浓度在0.5~50 μg/mL范围内与色谱峰面积呈良好的线性关系,相关系数分别为0.999 6、0.999 4,方法检出限分别为0.044、0.052 μg/mL。烟液中双乙酰和乙酰丙酰测定结果的相对标准偏差为2.5%~4.3%(n=6),样品加标回收率为95.0%~102.5%;气溶胶中双乙酰和乙酰丙酰测定结果的相对标准偏差为3.1%~4.6%(n=6),样品加标回收率为92.7%~102.3%。气溶胶中双乙酰和乙酰丙酰理论浓度与实测浓度具有较强的相关性(对于双乙酰r~2=0.990 1,对于乙酰丙酰r~2=0.994 7),说明双乙酰、乙酰丙酰烟液通过雾化直接转移至气溶胶中。该方法准确度高,重现性好,检出限低,可满足电子烟样品的检测需求。     

Quantification of amitriptyline, nortriptyline, and 10-hydroxy metabolite isomers in plasma by capillary gas chromatography with nitrogen-sensitive detection

A selective, sensitive method for the determination of amitriptyline and its metabolites is described. This method involves liquid-liquid extraction and capillary gas chromatography with nitrogen-sensitive detection. The detection limits of amitriptyline, nortriptyline, 10-hydroxy(E)amitriptyline, 10-hydroxy(E)nortriptyline, and 10-hydroxy(Z)nortriptyline were slightly less than 0.5 ng/ml in 1.0-ml plasma samples. The coefficients of variation for within-run and between-run analyses of samples containing 100 ng/ml were less than 12% and 9%, respectively. The method offers rapid analysis of individual isomers, increased sensitivity over high-performance liquid chromatographic methodology and the conveniences of the gas chromatographic technique.     

Determination of tributyrin and its metabolite butyrate in Wistar rat plasma samples by gas chromatography/mass spectrometry

A gas chromatographic (GC) method with mass spectrometric (MS) detection was developed for the determination of tributyrin and its metabolite butyrate in rat plasma. Following precipitation of plasma protein with acetonitrile, the analytes in the samples were separated on a DB-5ms capillary column with helium as carrier gas. Phenylmethylsulfonyl fluoride (PMSF), an inhibitor for serine proteases, papain and acetylcholinesterase, was found to be essential to inhibit the activity of enzyme(s) responsible for the hydrolysis of tributyrin in both rat and human blood samples. The enzyme inhibitor in 5 mM (final concentration) was added immediately into the blood samples after collection to prevent the hydrolysis. The linear concentration ranges for tributyrin and butyrate were 0.1-2.0 and 1-20 microM, respectively. The coefficients of variation for intra-day and inter-day assays for tributyrin were all <10%, and those for butyrate were also <10%, except for the lowest concentration (1 microM), which was less than 20%. The accuracy of all concentration determinations ranged from 96.0-110.0%. The limit of quantification (LOQ) was 0.1 microM for tributyrin and 1.0 microM for butyrate. This method could detect tributyrin and butyrate simultaneously, and represents an improvement in sensitivity for the detection of tributyrin compared with the previous gas chromatography-flame ionization detection (GC-FID) method.     

ICP-MS 法直接测定冰芯样品中超痕量镉

采用 ICP- MS法对冰芯样品中超痕量 Cd的直接测定进行了研究。确定了直接测定浓度为 pg/m L 级的 Cd的最佳仪器参数、载气流速、进样速度等与灵敏度之间的关系以及浓度和扫描参数对分析精度的影响。本方法对浓度 5～2 0 0 pg/m L Cd的分析 ,RSD<1 0 % ,回收率在 88%～ 1 0 5%之间 ,检测限为0 .1 5pg/m L     

Determination of Pesticides in the Rhizome of Traditional Chinese Medicines by Gas Chromatography with Electron Capture Detection

A simple and efficient gas chromatography method for the determination of 27 organochlorine and pyrethroid pesticides in traditional Chinese medicine was developed. Pesticide residues were extracted from the samples by oscillation and ultrasound, and purified by gel permeation chromatography and florisil solid phase extraction. The analysis was performed by gas chromatography with micro-electron capture detection. The purification conditions, such as the extraction and elution solvents, extraction methodology, and gel permeation chromatography conditions, were optimized. Traditional Chinese medicines were purified by different methods based on their composition. Under optimized conditions, the calibration graph was linear from 10 to 500 µg/L and the correlation coefficients varied from 0.9958 to 0.9997. The detection limits of these pesticides were between 0.09 and 1.82 µg/kg. The recovery of the pesticides spiked in various samples at four concentrations ranged from 73.2% to 106.4%, with relative standard deviations between 1.0% and 14.0%. This study indicates that the method is useful for determining pesticides in rhizome traditional Chinese medicines.