液相色谱-串联质谱测定纺织品中分散黄23和分散橙149

建立了高效液相色谱法(HPLC)和液相色谱-串联质谱法(LC-MS/MS)测定纺织品中分散黄23和分散橙149含量的方法.样品上的分散染料经氯苯蒸汽完全剥离纤维,浓缩后的残留物用甲醇定容,以0.1% H3PO4(或0.1%甲酸)和乙腈为流动相,经反相色谱柱分离后,用二极管阵列检测器(DAD)在420 nm处测定,并用电喷雾串联质谱确认.分散黄23和分散橙149的定量离子对分别为m/z 303/105和m/z 459/399.分散黄23和分散橙149的检出限(S/N=3):HPLC法为2.0和1.0 mg/kg,LC-MS/MS法都为1.0 μg/kg.HPLC在0.5～250 mg/L、LC-MS/MS在0.5～200 μg/L范围内,线性相关系数都大于0.995.方法的回收率在92.1%～98.7%之间,批间RSD都小于8.0%,含有分散黄23的阳性样品重复测试的RSD也小于8.0%.     

超高效液相色谱法和液相色谱-串联质谱法测定食品中奥比沙星残留量

食品样品用乙腈和磷酸盐缓冲溶液提取,经正己烷脱脂和HLB固相萃取柱净化处理后,用超高效液相色谱(UHPLC)-荧光检测器进行测定,阳性结果再经液相色谱-串联质谱法(LC-MS/MS)进一步确证。两种方法的线性范围分别为0.005～0.250,0.002～0.300 mg.L-1,检出限(3S/N)分别为0.005,0.002 mg.kg-1,回收率分别为80.2%～98.4%,74.5%～93.0%,相对标准偏差(n=10)均小于11.0%。     

超高效液相色谱-串联质谱法测定水产品中三聚氰胺残留量

建立超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定水产品中三聚氰胺残留的方法.采用ACQUITY UPLC BEH HILIC色谱柱(100 mm×2.1 mm, 1.7 μm),流动相为乙腈-0.5 mmol/L乙酸铵溶液(0.1%甲酸),流速为0.3 mL/min.采用电喷雾质谱检测,以正离子模式5 min完成质谱分析.实验结果表明,三聚氰胺在水产品中的检测限为0.05 mg/kg,在0.05～0.50 mg/kg添加水平时的加标回收率为63%～90%,测定结果的相对标准偏差均小于7.2%(n=6).     

海产品、底泥、海水中扑草净药物残留量的液相色谱-串联质谱检测

建立了海产品、底泥、海水中扑草净药物残留量的液相色谱-串联质谱检测方法。对海产品、底泥样品,采用快速溶剂提取仪(ASE)乙腈提取,凝胶渗透色谱(GPC)净化,液质联用仪(LC-MS/MS)分析;对海水样品采用酸化乙腈提取,氨基固相萃取柱净化,LC-MS/MS分析。实验结果显示,扑草净在浓度0.025～8.0ng/mL时,线性关系良好(R2=0.9999);海产品、底泥样品的方法测定低限为0.25μg/kg,3个加标水平下的平均回收率为90.0%～105.4%,相对标准偏差(RSD)为2.9%～5.3%;海水样品的方法测定低限为0.50μg/L,3个加标水平下的平均回收率为79.5%～99.6%,RSD为3.4%～11.9%。该方法简单、快速、准确,可用于海产品、底泥、海水样品中扑草净的筛选和测定。     

同位素内标法测定乳品中的三聚氰胺

本文以自制的15 N3-三聚氰胺作为内标,建立了测定乳制品中的三聚氰胺残留量的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。方法的线性范围为1～1 000ng/mL,回收率为95.6%～98.7%,相对标准偏差(RSD)为1.3%～2.5%,检出限(S/N=3)为1ng/mL。该方法灵敏度高,准确性好,为三聚氰胺的检测提供了一种可靠实用的方法。     

液相色谱-串联质谱法与气相色谱-串联质谱法测定茶叶中苦参碱残留量

建立了茶叶中苦参碱残留检测的两种前处理方法,比较了液相色谱-串联质谱(LC-MS/MS)与气相色谱-串联质谱(GC-MS/MS)检测茶叶中苦参碱残留量分析方法的适用性。结果表明,在添加标准样品10~100μg/kg 3个水平时,两种前处理方法的回收率和精密度无显著差别;GC-MS/MS和LC-MS/MS回收率分别为81%~85%、82%~86%,相对标准偏差(RSD)分别为4.6%~11.5%和2.9%~4.2%。结果表明两种样品前处理方法以及LC-MS/MS与GC-MS/MS检测均能满足茶叶中苦参碱残留量的测定,但采用前处理方法二,LC-MS/MS检测茶叶中苦参碱残留更具优势。     

高效液相色谱-二极管阵列检测法及高效液相色谱-电喷雾串联质谱法测定植物源性蛋白中残留的三聚氰胺

建立了高效液相色谱-二极管阵列检测器(HPLC-DAD)及HPLC-电喷雾串联质谱(ESI-MS/MS)测定植物源性蛋白中残留的三聚氰胺的方法。利用HPLC-DAD进行样品中三聚氰胺的初筛,利用HPLC-MS/MS进行确证。采用三氯乙酸溶液沉淀样品中的蛋白,同时提取目标分析物,质谱检测时样品再经强阳离子固相萃取柱富集净化。HPLC-DAD的检测低限为10 mg/kg,HPLC-MS/MS的检测低限为0.5 mg/kg;HPLC-DA的添加回收率为76%～88%,HPLC-MS/MS的添加回收率为72%～82%(基质匹配曲线校正),两种方法的添加回收率的相对标准偏差(RSD)为3.4%～6.4%。     

亲水作用色谱-串联质谱测定蔬菜中灭蝇胺及其代谢物三聚氰胺

建立了亲水作用色谱-串联质谱测定蔬菜中灭蝇胺及其代谢物三聚氰胺的方法.蔬菜样品匀浆后经甲醇-水提取,取适量酸化后提取液经阳离子固相萃取柱净化,洗脱液用氮气吹干,残留物用5 mL流动相定容.采用亲水作用色谱(Hilic)分离,在电喷雾-选择反应监测模式下,进行定性和定量分析.以基质校正曲线计算,添加浓度为0.04和0.20 mg/kg时,灭蝇胺的回收率为84.2%～101.3%; 相对标准偏差(RSD)为4.5%～10.7%;三聚氰胺的回收率为72.5%～97.1%; RSD为4.3%～10.8%;灭蝇胺和三聚氰胺的定量限分别为0.01和0.005 mg/kg.利用本方法检测了多种蔬菜样品中灭蝇胺、三聚氰胺的含量.     

气相色谱质谱法测定功能性饮料中的肌醇

研究建立了功能性饮料中肌醇的气相色谱/质谱(GC/MS)测定方法.样品经浓缩、硅烷化后以正己烷提取,用气相色谱/质谱仪外标法测定其含量.此方法回收率范围为90.0%～105%;变异系数为2.0%～5.0%.方法适合于功能性饮料中肌醇的分析测定.     

动物组织与水产品中头孢氨苄残留量的液相色谱-串联质谱检测

建立了牛肉、猪肉、肝脏、肾脏、脂肪、鱼肉、虾肉中头孢氨苄残留的LC-MS/MS检测方法.组织样品中的头孢氨苄用甲醇-0.2%偏磷酸 (体积比3 ∶ 7)溶液提取,采用Oasis HLB固相萃取小柱净化.分析样品以甲酸溶液(体积分数0.1%)-乙腈为流动相,经MG-Ⅱ C18色谱柱分离,在LC-MS/MS多反应监测模式下进行定性、定量分析,采用正离子扫描.头孢氨苄的定量下限为0.01 mg/kg,动物组织和水产品样品在0.01、0.05、0.1、0.2 mg/kg添加水平的回收率为75% ～106%,相对标准偏差(n=10)为5.3% ～12.1%.     

基体辅助激光解吸电离飞行时间质谱用于寡糖的分析

将基体辅助激光解吸电离飞行时间质谱这种新兴的质谱方法用于植物中寡糖的分析。比较了不同的样品制备方法和检测方法对分析结果的影响,给出各寡糖样品的分子量分布,单体和端基基团的分子量。     

Determination of bupivacaine and metabolites in rat urine using capillary electrophoresis with mass spectrometric detection

A method using capillary electrophoresis-mass spectrometry (CE-MS) was developed for the structural elucidation of bupivacaine and metabolites in rat urine. Prior to CE-MS analysis, solid-phase extraction (SPE) was used for sample cleanup and preconcentration purposes. Exact mass and tandem mass spectrometric (MS/MS) experiments were performed to obtain structural information about the unknown metabolites. Two instruments with different mass analyzers were used for mass spectrometric detection. A quadrupole time-of-flight (Q-TOF) and a magnetic sector hybrid instrument were coupled to CE and used for the analysis of urine extracts. Hydroxybupivacaine as well as five other isomerically different metabolites were detected including methoxylated bupivacaine.     

草药中 11种元素的聚焦微波辅助萃取-等离子体质谱法测定

利用ICP－MS对青钱柳叶、龙胆草以及秦皮中的11种金属元素进行测定。应用CEM Star-Ⅱ聚焦微波萃取系统,采用正交设计实验研究了温度、时间、料液质量体积比对浸取效率的影响。结果表明,温度是影响提取效率的主要因素,提取时间对某些元素影响也比较明显,但料液比对几乎所有元素的影响都很小。钒元素在微波萃取条件下溶出率很低。     

Accurate mass determination by multiple sprayers nano-electrospray mass spectrometry on a magnetic sector instrument

A new technique for accurate mass determination by using multiple sprayers nano-electrospray ionization mass spectrometry (nano-ESI-MS) on a magnetic sector instrument is described. Metal coated glass capillaries were used as nano-ESI sprayers. One of the sprayers was used for the reference compound solution, and others were used for the introduction of sample solutions. The spectra of the different compounds were obtained by shifting each sprayer's position relative to the sampling orifice. The accurate masses of several standard compounds were obtained with good accuracy, without problems arising from differences in ionization efficiency between the sample compounds and reference compound.     

Polarization induced electrospray ionization mass spectrometry for the analysis of liquid,viscous and solid samples

In this study, a polarization‐induced electrospray ionization mass spectrometry (ESI‐MS) was developed. A micro‐sized sample droplet was deposited on a naturally available dielectric substrate such as a fruit or a stone, and then placed close to (~2 mm) the orifice of a mass spectrometer applied with a high voltage. Taylor cone was observed from the sample droplet, and a spray emitted from the cone apex was generated. The analyte ion signals derived from the droplet were obtained by the mass spectrometer. The ionization process is similar to that in ESI although no direct electric contact was applied on the sample site. The sample droplet polarized by the high electric field provided by the mass spectrometer initiated the ionization process. The dielectric sample loading substrate facilitated further the polarization process, resulting in the formation of Taylor cone. The mass spectral profiles obtained via this approach resembled those obtained using ESI‐MS. Multiply charged ions dominated the mass spectra of peptides and proteins, whereas singly charged ions dominated the mass spectra of small molecules such as amino acids and small organic molecules. In addition to liquid samples, this approach can be used for the analysis of solid and viscous samples. A small droplet containing suitable solvent (5–10 µl) was directly deposited on the surface of the solid (or viscous) sample, placed close the orifice of mass spectrometer applied with a high voltage. Taylor cone derived from the droplet was immediately formed followed by electrospray processes to generate gas‐phase ions for MS analysis. Analyte ions derived from the main ingredients of pharmaceutical tablets and viscous ointment can be extracted into the solvent droplet in situ and observed using a mass spectrometer. Copyright © 2015 John Wiley & Sons, Ltd.     

Molecular weight determination of underivatized oligodeoxyribonucleotides by positive-ion matrix-assisted ultraviolet laser-desorption mass spectrometry

A Wiley-McLaren type time-of-flight mass spectrometer has been used for molecular weight measurements of several unprotected oligodeoxyribonucleotides using matrix-assisted UV laser desorption. Approximately 10 to 100 pmol of sample was required for recording their positive-ion mass spectra with a mass resolution in the range of 150 to 300 (Full width at half maximum) (FWHM). Little fragmentation was observed.     

亲水作用色谱-串联质谱法测定化妆品中三聚氰胺残留量

建立了化妆品中三聚氰胺的亲水作用色谱-质谱联用（HILIC-MS/MS）检测方法。样品经三氯乙酸溶液提取（脂溶性样品再经正己烷萃取)后,用混合型阳离子交换(MCX)反相固相萃取柱富集净化,用5 mmol/L乙酸铵水溶液(含0.1%甲酸)和乙腈作为流动相,以梯度洗脱方式在ZIC-HILIC色谱柱上实现分离,以电喷雾离子源正离子(ESI+)模式进行质谱分析。三聚氰胺在0.02～0.5 mg/L范围内呈良好线性关系,相关系数为0.9985;方法的检出限(LOD,信噪比(S/N)≥3)为5.0 μg/kg,定量限(LOQ,S/N＞10)为20.0 μg/kg;在0.01～0.1 mg/kg添加浓度范围内,三聚氰胺的平均回收率为84.7%～93.4%,相对标准偏差为4.5%～8.4%。该方法能满足化妆品中三聚氰胺残留量的检测。     

Software algorithm for automatic interpretation of mass spectra of glycerolipids

A new software algorithm for automatic interpretation of mass spectra of glycerolipids has been developed. The algorithm utilizes a user-specified list of parameters needed to process the spectra. The compounds in mass spectra are identified according to range of measured m/z values, after which the spectra are automatically corrected by the content of naturally occurring isotopes and ion intensities of identified compounds by response correction factors. Automatic processing of the spectra was shown to be accurate and reliable by testing with numerous spectra of glycerophospholipids obtained by liquid chromatography/electrospray ionization mass spectrometry and by comparing the results with manual interpretation of the spectra. If quantitative analysis using internal standards is performed, all the identified compounds in the sample are quantified automatically. A dilution factor may be defined for each sample and is applied to correct the alterations in sample concentration during sample preparation. Processing of several replicate spectra simultaneously produces mean results with standard deviations. The software may also be used to subtract the results of two analyses and to calculate the mean result of replicate subtractions. The algorithm was shown to save time and labor in repetitive processing of mass spectra of similar type. It may be applied to processing of spectra obtained by various mass spectrometric methods.     

Infrared laser post-ionization of large biomolecules from an IR-MALD(I) plume

A two-infrared laser desorption/ionization method is described. A first laser, which was either an Er:YAG laser or an optical parametric oscillator (OPO), served for ablation/vaporization of small volumes of analyte/matrix sample at fluences below the ion detection threshold for direct matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). A second IR-laser, whose beam intersected the expanding ablation plume at a variable distance and time delay, was used to generate biomolecular ions out of the matrix-assisted laser desorption (MALD) plume. Either one of the two above lasers or an Er:YSGG laser was used for post-ionization. Glycerol was used as IR-MALDI matrix, and mass spectra of peptides, proteins, as well as nucleic acids, some of which in excess of 10(5) u in molecular weight, were recorded with a time-of-flight mass spectrometer. A mass spectrum of cytochrome c from a water ice matrix is also presented. The MALD plume expansion was investigated by varying the position of the post-ionization laser beam above the glycerol sample surface and its delay time relative to the desorption laser. Comparison between the OPO (pulse duration, tau(L) = 6 ns) and the Er:YAG laser (tau(L) approximately 120 ns) as primary excitation laser demonstrates a significant effect of the laser pulse duration on the MALD process.     

基质辅助激光解吸电离飞行时间质谱研究（I）：林芳烃化合物

采用基质辅助激光解吸电离飞行时间质谱（ＭＡＬＤＩ－ＴＯＦ－ＭＳ）对杯芳烃化合物进行了分析。探讨了样品的制备条件、仪器操作参数等因素对测定结果的影响。２５种样品的质谱数据表明,利用ＭＡＬＤＩ－ＴＯＦ－ＭＳ可非常方便地得到灵敏度、分辨率、准确度均较高,且易于识别和解析的质谱图,为此类化合物的质谱表征提供和建立了一种新的高效分析方法。