A detection method for the determination of 20 kinds of cephalosporins in animal derived food was established with multiple stable isotope internal standards by liquid chromatography-tandem mass spectrometry. Cephalosporins were extracted from samples with methanol, and purified with octadecylsilane sorbent. An Ascentis C8 column was used for analyzing with 0.1% formic acid aqueous solution and acetonitrile as mobile phases. Analysis of cephalosporins were respectively performed on the positive and negative scan mode by multiple reactions monitoring. Results showed that the linear range of the methods was 5~100 μg/L for 17 kinds of cephalosporins with highly responsive, and 25~500 μg/L for 3 kinds of cephalosporins with lowly responsive. The determination coefficients of the linear equations ranged from 0.9913 to 0.9998. The limit of detection for 20 kinds of cephalosporins ranged from 1.0 to 20.0 μg/kg, and the limit of quantification ranged from 3.0 to 60.0 μg/kg in animal derived sample. The average recovery rate of 20 cephalosporins ranged from 78.08% to 115.47%, and the relative standard deviation ranged from 3.07% to 12.44%. The validated method was simple and accurate. It was suitable for the determination of 20 cephalosporins in animal food.

In order to ensure the accuracy of test results, the uncertainty determination of cephalosporins in chicken by high performance liquid chromatography-tandem mass spectrometry isotope internal standard method was evaluated. The source of uncertainty was evaluated and the mathematical model was established. Through quantitative analysis of each component of uncertainty, the uncertainty of each component was calculated. Finally, standard uncertainty was composited. When the content of cephalosporins in the sample was 250 μg/kg, the expanded uncertainty was 43.60~50.10 μg/kg. The results showed that uncertainty mainly derived from the measuring instruments (0.0762), repeatability (0.0337), analytical instruments (0.0250) and the addition of internal standards (0.0224). Among them the measurement instrument contributed the most to the uncertainty. It provided a reference basis for uncertainty evaluation of determination of cephalosporins by high performance liquid chromatography-tandem mass spectrometry isotope internal standard method.

目的 建立一种简便的核桃脂肪酸测定方法.方法 将核桃仁研磨至膏状,然后直接进行甲酯制备,经毛细管柱气相色谱分析,用面积归一化法测定脂肪酸百分含量.对一个泡核桃(Juglans sigillata Dode)样品进行对比测定,用GB 5009.168—2016《食品安全国家标准食品中脂肪酸的测定》中的归一化法和新方法分别平行测定20次,计算两组测定值之间的差异显著性,计算新方法的相对标准偏差,以检验新方法的准确性和精密度.结果 国家标准方法和新方法都检出了棕榈酸、硬脂酸、油酸、亚油酸和 α-亚麻酸5种脂肪酸,它们的平均含量(标准偏差)分别为:6.412％(0.041％)和6.403％(0.046％)、1.681％(0.016％)和1.679％(0.029％)、18.274％(0.146％)和18.274％(0.093％)、65.229％(0.168％)和65.244％(0.120％)、8.404％(0.028％)和8.400％(0.082％).t检验表明两组测定值之间无显著差异(P>0.05).新方法中5种脂肪酸的相对标准偏差均小于1.7％.结论 新建方法准确可靠,且因省去了耗时费力的粗脂肪提取步骤,非常适于快速处理大批量样品.

目的建立顶空-气相色谱(headspace gas chromatography, HS-GC)测定食用植物油中六号溶剂残留量的分析方法。方法样品经顶空处理进样,采用ZB-WAX毛细管柱分离,氢火焰离子化检测器检测,以外标法定量。通过实验优化样品前处理条件、顶空自动进样条件,确定最佳前处理方法、顶空平衡温度、平衡时间和样品称样量。结果六号溶剂检测线性良好,方法的检出限达2.0 mg/kg,样品的回收率为90.6%～104.0%,相对标准偏差为0.8%～2.0%。结论本方法简便、快速、重现性好,为食用植物油中的溶剂残留提供了可靠的检测方法。

建立一种准确、 快速的测定大米中农药马拉硫磷残留的方法.经丙酮溶液提取,用石墨化碳黑小柱和氟罗里硅柱双柱结合净化,氮吹浓缩,然后用气相色谱-质谱联用(GC-MS)检测.马拉硫磷标准质量浓度在0.1～1.0 mg/L范围内,线性关系良好,相关系数r达0.998.添加质量分数为0.1～1.0 mg/kg时,回收率在91.8％～119.5％,相对标准偏差(RSD)在3.1％～8.5％,定量检出限达0.05 mg/kg.新建的GC-MS法操作简单、 净化效果好、 灵敏度高、 检测效果良好.

目的 探讨2,4-二硝基苯肼(2,4-dinitrophenylhydrazine,DNPH)柱前衍生高效液相色谱法测定水中微量乙醛的方法.方法 将样品在60 ℃水浴中用DNPH衍生化20 min,由正己烷萃取,以乙腈∶水(52∶48,V∶V)为流动相,于365 nm波长下进行测定.结果 乙醛在0.015～1.00 mg/L浓度范围内线性关系良好,相关系数r为0.9999,加标回收率为80.2％～99.8％,相对标准偏差为4.6％～7.4％,方法最低检出浓度为0.003 mg/L.结论 该方法样品前处理简单快捷、检出限低、灵敏度高,能够满足生活饮用水卫生规范的要求,并且能够同时测定大批量样品,为解决国家标准中检测方法最低检出限与其乙醛的限值相矛盾的问题提供参考.

新建一种测定地下水中2,4-和2.6-二硝基甲苯的液液萃取-气相色谱法.甲苯作溶剂萃取水中的2,4-和2.6-二硝基甲苯,经DB-1701色谱柱分离,电子捕获检测器(ECD)检测.经过优化的色谱方法测定结果显示,2,4-和2.6-二硝基甲苯的检出限都为0.05μg/L,均具有较好的线性关系,相关系数都大于0.999;2,4-和2.6-二硝基甲苯的精密度分别为3.4％～12.6％和4.0％～15.5％;2.4-和2,6-二硝基甲苯的加标回收率分别是75.4％～126.0％和71.5％～122.6％.本方法准确、 灵敏、 快速,可为地下水样中2,4/2,6-二硝基苯的污染评价提供技术支持.

目的 建立电感耦合等离子发射光谱法测定乳扇中铝含量的分析方法.调查市售样品中铝的含量是否异常.方法 采用湿式消解法处理乳扇样品,电感耦合等离子发射光谱测定样品中铝的含量,同时进行精密度实验和加标回收实验.测定市场收集的乳扇样品中铝的含量,并与严格按云南省地方标准(DBS53/010-2016)制作的乳扇样品进行比较.结果 铝在0～10 mg/L范围内线性关系良好,相关系数r达0.999928,方法的检出限为0.5 mg/kg,定量限为1.5 mg/kg,精密度为2.5％～3.1％,加标回收率在96.6％～105.0％之间.按地方标准制作的乳扇样品中铝含量较低,在3.2～5.3 mg/kg之间,部分市场收集的样品中铝含量偏高.结论 本方法操作简便、结果准确,可作为乳扇中铝含量检测的方法.乳扇应严格按照地方标准制作.

In this study,we intended to develop a method for the determination of microcystin in lake water by high performance liquid chromatographic(HPLC). The trichloroacetic acid solution with 0.5mL/L was applied as mobile phase. Microcystin was separated by Agilent Eclipas XDB C18 column and determined at 238nm wavelength by VWD. The detection limit of the method reached 0.4μg/L. There was a good linearity within the range of 0.4μg/mL to 2μg/mL with the correlation coefficient of 0.998. The recoveries were between 84.2% and 92.0% at the spiking level of 0.4μg/mL to 1.8μg/mL,and the relative standard deviation ranged from 0.2% to 3.2%. The method built in this study is sensitive,accurate and easy to operate.

A method for the determination of active pentanol and furfural in wine samples by chromatography was studied. The ZB-WAX column and hydrogen flame ionization detector was selected. The results showed that the recovery of active pentanol ranged between 97.9%-109.4% and the recovery of furfural ranged between 2.1%-4.9%. The detection limits were 5mg/L. The relative standard deviations of active pentanol ranged from 2.6% to 3.2% and the relative standard deviations of furfural ranged from 4.1% to 4.9%. The method is simple,quick,accurate and safe and it can be applied for the determination of active pentanol and furfural in wine samples.

改进检测白酒中氨基甲酸乙酯含量的气相色谱-质谱法(GC-MS).样品经二氯甲烷提取,用旋转蒸发仪浓缩至近干,乙腈溶解,正已烷去除杂质,然后用气相色谱-质谱联用法检测.氨基甲酸乙酯标准浓度在0.1～1 mg/L范围内,线性关系良好,相关系数r达0.999.添加浓度为0.01～0.1 mg/kg时,回收率为77.7％～95.2％,相对标准偏差(RSD)在4.0％～6.3％之间,定量检出限低于0.01 mg/kg.改良后的GC-MS法操作简单快速、经济节约、灵敏度高.

目的建立农产品中螺虫乙酯及其3种代谢产物的超高效液相色谱-串联质谱检测方法。方法样品经乙腈涡旋提取,采用乙二胺-N-丙基硅烷（primary secondary amine,PSA）和HC-C 18 分散固相萃取剂净化,经超高效液相色谱串联质谱仪多反应监测模式检测,外标法定量。结果螺虫乙酯及其3种代谢产物在0.1~100μg/L质量浓度范围内与其呈良好的线性关系（r~2＞0.999）,检出限为0.1μg/kg,螺虫乙酯代谢产物S1定量限为1.0μg/kg,其余为0.2μg/kg,在添加水平为1.0、25、50μg/kg时,平均回收率为82.5%~99.1%,测定结果的相对标准偏差为1.3%~8.4%（n=6）。结论该方法简单、快速,重复性好,灵敏度和准确度均能满足农产品中螺虫乙酯残留量的测定。

Objective To establish a method for the determination of benzo(a)pyrene in vegetable oil by gas chromatography-tandem mass spectrometry (GC-MS/MS).Methods Vegetable oil samples were extracted with petroleum ether,and the extracts were purified by neutral alumina column and concentrated with blowing nitrogen to constant volume.Then the multiple reaction monitor (MRM) mode was applied for detection by using GC-MS/MS.The target ion pair of mass spectrometry was selected.Results There was a good linear relationship between peak area and concentration of benzo(α)pyrene when the mass concentration ranged from 0.1 μg/L to 20 μg/L.The limit of quantification (LOQ) of method was 1.0 μg/kg.The average recoveries of benzo(α)pyrene in 3 spiked levels were 89.7％～117.8％,and the relative standard deviations were 3.2％～9.0％.Conclusion The established method is precise and accurate,which can be used for the accurate determination of benzo(α)pyrene in edible vegetable oil samples.

通过优化快速溶剂萃取法(ASE)条件萃取茶叶中茶多酚,同时结合国家标准方法GB/T8313-2008中的福林酚比色法对其含量进行了测定,用t检验法对ASE法与国标方法进行了检验,结果表明,两者无显著性差异,可将ASE法用于测定茶叶中茶多酚时的提取.同时用此方法对9个样品进行了测定.ASE方法快速,简便,减少人体接触试剂的机会,可用于实际样品检测.

用气相色谱法测定酒中的甲醇、乙酸乙酯、己酸乙酯等10种物质,采用ZB-WAX毛细管柱法对酒样中甲醇、乙酸乙酯、己酸乙酯等10种成分进行检测.经优化的色谱方法测定,结果显示,酒样中甲醇、乙酸乙酯、己酸乙酯等10种物质的检出限达3mg/L,相关系数均在0.9990以上,该方法的相对标准偏差在2.2%~9.9%之间,加标回收率在82.3%~118.6%之间,该法具有较高的准确度和精密度,所得结果可靠.可用于实际酒样品中甲醇、乙酸乙酯、己酸乙酯等10种物质的测定.

A method for the determination of acetaldehyde and acrolein in surface water by headspace gas chromatography was studied.As a result,the temperature of 80 ℃,the balance time of 20 min,the NaCl amount of 4 g and the water volume of 10 mL were chosen as the optimization of headspace conditions.The detection limits was 0.05 mg/L of acetaldehyde and 0.08 mg/L of acrolein.The results showed that the re-covery of acetaldehyde ranged between 84.8% - 109.1% and the recovery of acrolein ranged between 79.2% -108.3%.The relative standard deviations were ranged from 2.4% to 10.7%.

[Objective] The aim was to establish a method for detecting 17 phthalates esters(PAEs) in edible vegetation oil.[Method] Amethod for the determination of PAEs in edible vegetation oil by gas chromatography coupled with triple quadrupole mass spectrometry(GC-MS-MS) was established and samples were tested.[Result] The linear range of detection changed from 10 to 1 000 μg/L (r >0.999).The detection limits of samples of the 17 kinds of PAEs were 0.2 mg/kg.The average recoveries of three different concentrations (1.0, 5.0and 10 .0 mg/kg) were ranged between 80.40% to 110.9% and the relative standard deviations were ranged from 2.4% to 8.3%.[Conclusion] This method is simple, quick, accurate, which can be applied to the determination of 17 PAEs in walnut oil, rapeseed oil, corn oil andother edible vegetation oil samples.

采用气相色谱-三重四极杆质谱联用法测定核桃油中酚类抗氧化剂,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3种酚类抗氧化剂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品的纯度和样品的回收率.该评估模型为气相色谱-三重四极杆质谱联用法的不确定度评估提供了参考依据.

ABSTRACT:Objective To establish a method for simultaneous determination of 10 residual penicillin in dairy products by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The sample was extracted with acetonitrile and degreased with saturated acetonitrile n-hexane and filtered through 0.22μm millipore membrane. The filtrate was detected by ultra high performance liquid chromatography-tandem mass spectrometry, identified by electrospray ionization (ESI) in positive mode using multiple reactions monitoring mode, and quantified with external standard method. The sample extract was separated on a C18 column by gradient elution in 20 min with acetronitrile-water (containing 0.1% formic acid and 5 mmol/L ammonium acetate) as mobile phase.Results The calibration curve of the 10 penicillins residues showed a good linearity in the range of 0.1μg/L~20.0μg/L in various dairy products in the matrix with the correlation coefficientr2>0.999. The detection limit of the method was 0.2μg/kg~1.0μg/kg for liquid milk and 1.0μg/kg~5.0μg/kg for milk powder. The recoveries of spiking levels ranged from 70.2% to 108.2%, and the relative standard deviation (RSD) was less than 15%. ConclusionThe method for determination of residues of 10 penicillin antibiotics in dairy products is simple, rapid and accurate, and could satisfy the requirements for monitoring of penicillin residuesrequirements for monitoring of penicillin residues

本文建立了一种气相色谱(GC)和气相色谱-质谱(GC-MS)法测定饮料中香兰素和乙基香兰素含量的方法.无色样品经乙醚萃取、离心、取上清液浓缩定容经0.22 μm有机相滤膜净化进样,有颜色样品经乙醚萃取、离心、取乙醚上清液浓缩至近干,丙酮溶解混匀,过石墨化碳黑柱净化,浓缩定容,分别进GC-FID和GC-MS测定及确证,外标法定量.GC法测定香兰素和乙基香兰素的添加回收率范围为80％ ～105％,相对标准偏差(RSD)小于6.0％.GC-MS法测定香兰素和乙基香兰素的添加回收率范围为81％～110％,相对标准偏差(RSD)小于6.0％.该方法中GC仪器操作简单、成本较低,可广泛应用于饮料中香兰素和乙基香兰素日常检测,GC-MS法采用选择离子扫描(SIM)排除GC法测定的假阳性结果,使测定结果更准确可靠,两种方法互补使用,适合饮料中香兰素和乙基香兰素的日常分析检测和质量控制.