Uncertainty Evaluation of Determination of Microcystin MC-LR in Environmental Samples by Solid Phase Extraction-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

To assess uncertainty of determination of MC-LR in environmental samples by solid phase extraction- ultra performance liquid chromatography- tandem mass spectrometry,the sources of the uncertainty were evaluated firstly,and the expanded uncertainty was calculated finally.The results show that when MC-LR concentration in the water samples was 0.50 μg/L,the expanded uncertainty was 0.00628 μg/L(k=2).

Determination of thyreostats in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry

Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.

Rapid Determination of Three Kinds of Microcystins in Environmental Water Samples by Disk SPE-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A method of rapidly detecting three kinds of microcystins( MCs) in environmental water samples by using disk SPE- ultra high performance liquid chromatography- tandem mass spectrometry( UPLC- MS / MS) was established. Firstly,environmental water samples were extracted by disk SPE column( C_(18)),and three kinds of MCs were separated by Waters BEH C_(18) chromatographic column with acetonitrile- 0. 2% formic acid solution as the mobile phase. After the gradient elution separation,the external standard method was used for quantitative and qualitative analysis under MRM of UPLC- MS / MS. The results showed that the three kinds of MCs in the range of 0. 05- 10 μg / L showed good linear relation,and the correlation coefficients were higher than 0. 999 4,while the method detection limit was 0. 04 ng / L. Under 0. 1,1,and 5 μg / L standard addition for the same environmental sample,the average recovery was 82. 8%- 108. 8%,and the relative standard deviation of determination results was2. 1%- 10. 1%( n = 6). This method is rapid,sensitive and accurate,so it can be effectively applied in the monitoring of MCs in environmental water samples.

Lysophosphatidylcholine Biomarkers of Lung Cancer Detected by Ultra-performance Liquid Chromatography Coupled with Quadrupole Time-of-flight Mass Spectrometry

Centrifugal ultrafiltration after methanol extraction of whole plasma was used as an optimal condition for the preparation of blood plasma before metabonomic studies. The plasma samples from 102 lung cancer patients and 34 healthy volunteers were prepared with this approach. With ultra-performance liquid chromatography（UPLC） coupled with quadrupole time-of-flight mass spectrometry（Q-TOF MS） analysis, the samples were investigated in order to find potential disease biomarkers. After data acquisition, orthogonal signal correction partial least squares models were built to differentiate the healthy volunteers from lung cancer patients and to identify metabolites that showed significantly different expression between the two groups. Several metabolite ions were identified as potential biomarkers according to the variable importance in the project（VIP） value in both ion modes. Five lysophosphatidylcholines were further identified as specifically lysoPC 16：0, isomer of lysoPC 16：0, lysoPC 18：0, lysoPC 18：1 and lysoPC 18：2. These results suggest that UPLC coupled with Q-TOF MS is an effective technique for the analysis of plasma metabolites in metabonomic studies.

UPLC/MS-MS结合QuEChERs检测可食性鸡组织中8-α-羟基妙林残留

为准确测定可食性鸡组织中8-α-羟基妙林的残留量,试验建立了一种高效液相色谱-串联质谱(UPLC/MS-MS)结合QuEChERs的快速检测方法。样品经酸化丙酮提取,Bond Elut QuEChERs柱净化,氢氧化钠碱溶液水解,乙酸乙酯反萃取,高效液相色谱-串联质谱仪测定。结果显示:鸡肉和鸡肝中8-α-羟基妙林在50~200μg/kg浓度范围内,方法具有良好的线性相关性,相关系数≥0.99;在可食性鸡组织中的检出限为10~20μg/kg,定量限为25~50μg/kg;8-α-羟基妙林在50、100和200μg/kg添加水平下平均回收率为65.07%~103.16%,批内、批间变异系数均≤20%。研究提示:建立的方法操作简便、结果准确,满足了兽药残留药物痕量检测方法规定要求,适用于可食性鸡组织中8-α-羟基妙林的残留量测定。

UPLC-MS-MS法测定花生中黄曲霉毒素的不确定度评定

对应用超高液相色谱串联质谱法测定花生中4种黄曲霉毒素含量的测量不确定度进行评定。根据JJF 1135-2005《化学分析测量不确定度评定》和JJF 1059.1-2012《测量不确定度评定与表示》中的有关规定和基本程序,建立测定花生中4种黄曲霉毒素含量的数学模型,依据影响测量不确定度的来源,对各个不确定度分量进行评定和分析,给出了1μg/kg的检测水平下,超高液相色谱串联质谱法测定花生中4种黄曲霉毒素测定结果的扩展不确定度。通过比较各个分量不确定度,发现实验过程中最小二乘法拟合带来的不确定度影响最大。

UPLC-MS-MS快速测定烟草中131种农药残留量

采用QuEChERS-超高效液相色谱-串联质谱法建立了烟草中131种农药残留的同时测定方法,样品用1%乙酸-乙腈萃取,氯化钠和无水硫酸镁盐析,经PSA固相分散吸附剂净化,采用正负离子多反应监测(MRM)模式检测,外标法定量。结果表明,131种农药在1~200μg/L范围内线性关系良好,决定系数(r^2)均大于0.99,方法的检出限为0.05~24.50μg/kg,131种目标物的平均回收率为65.3%~112.4%,RSD为3.2%~7.3%。该方法简便、快速、灵敏、可靠,适用于烟草中131种农药残留的快速测定。

QuEChERS法和UPLC-MS-MS法快速测定棉籽中的马拉硫磷

[目的]建立超高效液相色谱-串联质谱(UPLC-MS-MS)对棉籽中马拉硫磷的检测方法。[方法]棉籽样品经乙腈提取,正交试验优化QuEChERS净化方法,正离子多反应监测(MRM)模式测定。[结果]该方法在0.01~1.00 mg/L线性关系良好,相关系数为0.999 9,最低检出量为2μg/kg,最低检出浓度为10μg/kg,加标回收率82.29%~90.64%,相对标准偏差在5.25%~14.64%。[结论]该方法简便、快速、准确、灵敏,节省有机溶剂,环境友好,适合大批量棉籽中马拉硫磷的检测需要。

UPLC-MS-MS法快速测定甘蓝和土壤中虱螨脲的残留量

建立了甘蓝（Brassica oleraceaL．）和土壤中虱螨脲残留的超高效液相色谱-三重四极杆串联质谱（UPLC—MS—MS）快速检测的方法。样品用酸化乙腈提取，以QuEChERS法净化，超高效液相色谱一串联质谱电喷雾负离子模式检测。结果表明，虱螨脲在5-500μg/L范围内，浓度和响应峰面积线性关系良好。在0．01、0．02、0．1和0．5mg／kg4个添加浓度下，平均回收率在78．5％～113．6％．相对标准偏差（RSD）为2．5％-8．5％（n=6），虱螨脲在甘蓝和土壤中的定量限（LQD）均为0．01mg／kg。该方法适用于甘蓝和土壤中虱螨脲的检测．

UPLC-MS-MS法快速测定大白菜和土壤中氰氟虫腙残留

建立大白菜和土壤中氰氟虫腙残留的超高效液相色谱-三重四极杆串联质谱（UPLC-MS-MS）快速检测的方法。样品用酸化乙腈提取、QuEChERS法净化,超高效液相色谱-串联质谱电喷雾正离子模式检测。结果表明,氰氟虫腙在5-500μg/L范围内浓度和响应峰面积线性关系良好,相关系数为0.999。在0.005、0.01、0.05、0.2和1.0 mg/kg添加浓度下,平均回收率87.2%-113.4%,相对标准偏差（RSD）为0.6%-9.3%（n=5）,氰氟虫腙在大白菜和土壤中的定量限（LQD）均为0.005 mg/kg。该方法适用于大白菜和土壤中氰氟虫腙的检测。

UPLC-MS-MS法测定水产品中克百威及其代谢物

采用超高效液相色谱-串联质谱技术建立同时测定水产品中克百威及其代谢物(3-羟基克百威、3-酮基克百威和呋喃酚)含量的方法。样品经乙腈提取,正己烷脱脂,HLB固相萃取柱净化,色谱柱分离,电喷雾串联四极杆质谱进行检测,采用多反应监测分析,并对液质分离条件及参数和样品前处理条件进行优化。结果显示,克百威及其代谢物在0.08～100ng/mL范围内线性良好(0.998 3～0.999 7)。在0.25～2.5μg/kg时,平均加标回收率在87.9%～96.1%,RSD值在1.4%～9.5%。该方法测定克百威、3-羟基克百威、3-酮基克百威和呋喃酚的检出限均为0.25μg/kg。该方法快速、准确、灵敏,可用于水产品中克百威及其代谢物残留量的测定。

UPLC-MS-MS法测定怀山药中去甲乌药碱的含量

目的:建立超高效液相色谱-串联质谱(UPLC-MS-MS)法测定怀山药中去甲乌药碱含量的测定方法。方法:样品用0.1%高氯酸溶液提取、MCX固相萃取柱净化,5%氨水甲醇溶液洗脱,洗脱液水浴上氮吹干后用50%甲醇水溶液(含0.1%甲液)复溶。采用Waters BEH C_(18)超高效液相色谱柱(150 mm×2.1 mm,1.7μm),流动相为乙腈-0.1%的甲酸水溶液进行梯度洗脱分离,柱温30℃,流速为0.3 mL·min^(-1),以非诺特罗作为内标进行定量。结果:去甲乌药碱的线性范围为1~100 ng·mL^(-1)(r=0.9993),检出限为0.3μg·kg^(-1),定量限为1μg·kg^(-1);样品加标回收率为86.8%~91.8%,相对标准偏差为2.1%。结论:本方法净化效果好,灵敏度高,线性范围广,重复性好,能够满足怀山药中去甲乌药碱含量测定要求。

不同产地地参核苷类成分的UPLC-MS-MS定性定量分析

该文建立1种地参中胞苷、尿嘧啶、腺嘌呤、尿苷、鸟苷和腺苷6种核苷类成分的超高效液相色谱-串联质谱(ultra performance liquid chromatograph tandem mass spectrometer,UPLC-MS-MS)定性定量分析方法。采用纯水超声提取,以甲酸水溶液(pH4.0)-甲醇为流动相,在Agilent SB-C_(18)色谱柱上梯度洗脱,正离子多反应监测模式测定,并采用差异性分析、聚类分析和相关性分析对测定结果进行比较。结果显示:6种核苷类成分在各自的质量浓度范围内线性关系良好,相关系数为0.9952~0.9999,检出限为0.07 ng/mL~8.34 ng/mL,加标回收率为96.30%~103.71%,相对标准偏差值为0.68%~2.32%。核苷含量结果显示不同产地间存在一定差异性(p<0.05),其中江苏徐州(S7)样品中核苷总量最高;6种核苷类成分中尿苷和鸟苷含量居首,分别占比核苷总量的35.60%和34.60%,是地参中主要的核苷类成分。该方法定性定量准确、分析速度快、灵敏度高,可用于不同产地地参中6种核苷类成分的分析。

UPLC-MS-MS检测饮料中的4-甲基咪唑及其同分异构体2-甲基咪唑

建立超高效液相色谱-串联质谱（ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS-MS）法检测饮料中的4-甲基咪唑（4-（5-）-methylimidazole,4-Mel）及2-甲基咪唑（2-methylimidazole,2-Mel）的方法.以水溶解样品,OASIS（R）MCX固相萃取柱富集净化后,进入UPLC-MS-MS检测,内标法定量.在优化的条件下,以ACQUITY UPLC（R）HILIC色谱柱（2.1 mm×100mm,1.7 μm）为分析柱,乙腈和5 mmol/L甲酸铵溶液为流动相,在电喷雾正离子多反应监测模式进行检测.结果表明,4-Mel和2-Mel在9～500 ng/mL范围内线性关系良好.方法的定量限为3.0 μg/kg.在4个加标水平下,3种不同基质饮料中4-Mel和2-Mel的平均回收率分别为97.3％和93.7％,相对标准偏差分别为3.8％和3.4％,该方法适用于饮料中4-Mel和2-Mel的检测.利用该方法对市售饮料中4-Mel和2-Mel的含量进行检测,在软饮料、焦糖色饮料及咖啡饮料中检出含有4-Mel或2-Mel;而功能性饮料中未检出4-Mel和2-Mel.

UPLC-MS-MS法测定八宝粥罐头中乙二胺四乙酸二钠残留量

建立超高效液相色谱-串联质谱法测定八宝粥罐头中乙二胺四乙酸二钠(ethylenediaminetetraacetic acid disodium,EDTA-2Na)残留量的检测和确证方法。试样中残留的EDTA-2Na用水高速匀浆提取,提取液经三氯化铁衍生化、三氯甲烷和MAX阴离子交换柱净化后,用超高效液相色谱-串联质谱仪检测和确证,外标法定量。EDTA-2Na质量浓度在1.0~50.0 μg/m L范围内时,线性关系良好,EDTA-2Na的相关系数(R2)为0.992 2。在20~400 mg/kg添加范围内,样品平均加标回收率在79.4%~105.3%之间,相对标准偏差为7.93%~9.94%。EDTA-2Na的最低检出限为20 mg/kg。该方法具有灵敏、准确、稳定等优点,可用于八宝粥罐头中EDTA-2Na残留量测定。

UPLC-MS-MS法测定饲料、原料乳及乳制品中3种氯霉素类药物残留

建立超高效液相色谱-质谱联用法检测饲料、牛乳及广义乳制品中氯霉素类药物残留的通用检测方法。研究适用于检测饲料、原料乳、液体乳、发酵乳、含乳饮料、乳粉、奶片、冷冻饮品中氯霉素类药物的前处理方法以及适用的超高效液相色谱及质谱条件。样品经低温冷冻沉淀蛋白质后,乙腈提取,饱和氯化钠使乙腈、水分层,取上清液氮气吹干定容后,正己烷除脂,乙腈、水梯度洗脱,电喷雾负离子多反应监测模式进行检测。氯霉素、甲砜霉素、氟甲砜霉素定量限0.1 μg/kg。氯霉素类药物添加范围0.1~2.5 μg/kg时,基质效应为57.9%~139.2%,回收率为64.3%~120.2%,相对标准偏差为2.1%~10.0%。该方法具有简单方便、检测周期短、适用于更广泛样品检测的特点。

Detecting N-nitrosamines in water treatment plants and distribution systems in China using ultra-performance liquid chromatography-tandem mass spectrometry

N-nitrosodimethylamine （NDMA） and several other N-nitrosamines have been detected as disinfection by-products in drinking waters in many countries around the world. An ultra-performance liquid chromatography- tandem mass spectrometry method with solid phase extraction sample preparation was developed to study the occurrence of N-nitrosamines in several water treatment plants and distribution systems in China. Isotope labeled N-nitrosodi-n-propylamine-dl4 （NDPA-dl4） was selected as the internal standard for quantification. The solid phase extraction procedures including pH, enrichment process and MS/MS parameters including capillary voltage, cone gas flow, cone voltage, collision energy were optimized to give average recoveries of 26% to 112% for nine N- nitrosamine species. The instrument detection limits were estimated to range from 0.5 to 5μg.L-1 for the nine N- nitrosamine species. NDMA and several other N-nitrosa- mines were found at fairly high concentrations in several water treatment plants and distribution systems. NDMA was found in all locations, and the highest concentrations in cities B, G, T, and W were 3.0, 35.7, 21.3, and 19.7 ng. L 1, respectively. A wide range of N-nitrosamines concentrations and species were observed in different locations. Higher concentrations of N-nitrosamines were detected in distribution systems that were further away from the treatment plants, suggesting that the contact time between the residual disinfectant and natural organic matter may play an important role in the formation of these compounds.

SA-UPLC-MS-MS联用测定奶粉中双氰胺的残留量

建立超高效液相色谱．串联质谱（UPLC—MS—MS）检测奶粉中双氰胺残留量的检测方法。以氘代试剂为内标，样品经氨化乙腈萃取后，平行定量浓缩仪浓缩，用正己烷脱脂，采用UPLC．MS—MS选择反应监测（sRM）正离子模式测定。双氰胺的检出限可达10μg／kg，最低定量限可达501ag／kg。在10-1000ng／mL范围内峰强度与质量浓度的线性关系良好（r〉0．990）。方法的平均回收率在99．6％-102．3％之间。方法简单、快速、稳定、准确、灵敏度高，能够满足日常工作中奶粉双氰胺的检测要求。

UPLC-MS-MS法测定血液中5种吩噻嗪类药物

建立了超高效液相色谱串联质谱法测定血液中5种吩噻嗪类药物的方法。血液样品经过沉淀蛋白后,在HSS SB C18色谱柱上,经乙腈–0.1%甲酸水溶液梯度洗脱分离,用液相色谱–串联质谱仪以电喷雾电离(ESI+)、多反应监测(MRM)方式进行分析。血液样本中异丙嗪、泰尔登、氯丙嗪、奋乃静、三氟拉嗪提取回收率分别为62%～65%,71%～97%,66%～107%,72%～95%,77%～96%,检出限分别为0.02,0.01,0.01,0.01,0.01 ng/mL。测定结果的相对标准偏差小于7%(n=6)。线性范围为0.05～20 ng/mL,相关系数大于0.999。该方法适用于血液中吩噻嗪类药物的分析。

Simultaneous Determination of Six Compounds in Rat Plasma by Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry: Application in the Pharmacokinetic Study of Qing Gan-Shu Yu-Fang

A rapid and high selective ultra-performance liquid chromatography(UPLC)with tandem mass spectrometry method for simultaneous determination of six compounds including albiflorin,paeoniflorin,picroside I,picroside II,saikosaponin A,and saikosaponin D in rat plasma was developed and validated using butyl p-hydroxybenzoate as an internal standard.One-step direct protein precipitation with acetonitrile was used to extract the compounds from the rat plasma samples.Chromatographic separation was achieved using an ACQUITY UPLC BEH C18 column(100 mm×2.1 mm,1.7μm)at a flow rate of 0.4 m L/min,using gradient mode containing 0.1%formic acid in water and acetonitrile were used as the Mobile phase A and B.Electrospray ionization in negative ion mode and multiple reaction monitoring were used to identify and quantify active components.Calibration curves showed good linearity(R^2>0.9908)over a wide concentration range for all compounds.The intra-and interday precision(relative standard deviation)ranged 2.4%–7.0%and 2.6%–8.0%,respectively.The accuracy(relative error)was from-13.0%to 13.2%at all quality control levels.The recovery ranged from 81.1%to 92.5%.The validated method was successfully applied to pharmacokinetic study in rats after oral administration of Qing Gan-Shu Yu-Fang.The results show that one can draw a conclusion that these six active ingredients can be quickly absorbed and play a pharmacodynamic role rapidly in vivo.