微波等离子体炬质谱直接分析水中镉的研究

建立了一种测量水中痕量镉的质谱电离新方法。以微波等离子体炬(MPT)为离子源,结合质谱仪器可直接分析水样而无需任何样品预处理。水样直接通过雾化器雾化形成气溶胶,气溶胶经加热冷却循环及浓硫酸干燥后,由MPT中心管道引入等离子体,产生的离子采用四极杆质谱仪(QMS)检测,得到镉的MPT特征质谱。根据镉的特征质谱进行定量分析。结果表明,114Cd的信号强度与溶液中镉离子浓度在300~3 000ng/L范围内呈良好线性关系,相关系数可达0.994 96,检出限(LOD)为72.7 ng/L。对实际水样(自来水、太湖湖水、赣州龙南井水、矿泉水)进行分析,加标回收率为90.6%~112.2%,10次测量的相对标准偏差(RSD,n=10)为7.1%~21.5%,单个样品测试可在2~3 min内完成。因此,MPT质谱法对水中有害金属镉的快速测量具有一定优势,作为传统ICP质谱检测的有力补充,可以发展成为在线分析方法,应用于环境水、生活水质量监控等领域。     

盐析效应结合顶空气相色谱质谱法测定香精香料中甲醇含量

利用盐析效应结合顶空-气相色谱/质谱联用仪,建立了一种快速、准确检测香精香料中甲醇含量的方法.方法以5 mol/L NaCl溶液为顶空基质校正剂,试验得线性范围为0.8~200 ng/mL(r~2=0.999 9,n=6),检出限为0.25ng/mL,定量限为0.84 ng/mL,日内精密度1.8%,日间精密度4.2%,样品加标回收率为96.51%~114.98%.测得随机抽取的10个含有香精香料样品中甲醇的质量浓度在0.0~8.4 ng/mL之间.方法无需前处理,灵敏度高,选择性好,定性准确,适用于香精香料中甲醇含量的测定.     

两种微波等离子体炬质谱测定水中铅的对比研究

建立了一种新型的能够灵敏分析水中痕量铅的质谱方法,以微波等离子体炬(MPT)为离子源,可无需样品预处理而直接分析水样。样品经雾化和去溶后由MPT的中心管道引入等离子体,离子由国产的四极杆质谱仪(Q-MS)检测,得到铅的MPT特征质谱。定量结果表明,该方法的检出限为20 ng/L,线性范围为200~1 000 ng/L,相对标准偏差(RSD)为5.3%;所得定量指标优于相同条件下商用的线性离子阱质谱(LTQ-MS)测试结果,且四极杆质谱仪上所得的铅离子特征质谱信号更简单、易归属,无需复杂的多级串联质谱加以确认。这种MPT可与国产质谱仪器相结合发展成为一种低成本的现场检测铅的质谱仪器,在环境监控、饮用水检验等方面具有一定的应用价值。     

基于中性解吸-电喷雾萃取电离质谱直接检测蜂蜜中的四环素

基于中性解吸-电喷雾萃取电离质谱(ND-EESI-MS)建立了无需样品预处理即可直接检测蜂蜜中四环素的方法. 测定结果表明, 加标蜂蜜四环素样品在20~1000 ng/mL浓度范围内线性关系良好(R²>0.997), 检出限为1.08 ng/mL; 加标浓度为50, 500和1000 ng/mL蜂蜜样品的回收率分别为94.26%, 98.38%和103.00%, 精密度(RSD)分别为3.28%, 1.39%和1.12%. 应用此方法对8种市售蜂蜜进行检测, 发现2种蜂蜜中含有痕量的四环素, 其余蜂蜜均未检出, 而应用高效液相色法在这8种市售蜂蜜中均未检出四环素. 本方法无需经过复杂的样品预处理, 灵敏度高、 精密度好、 分析速度快且特异性强, 能够承受蜂蜜中复杂基体的影响, 是一种快速检测蜂蜜中四环素的方法.     

中性解吸电喷雾萃取电离质谱法直接检测蜂蜜中的敌敌畏

采用中性解吸电喷雾萃取电离质谱( ND-EESI-MS)技术,在无需样品预处理的条件下,建立了对蜂蜜中敌敌畏直接快速检测的方法。在正离子模式下,敌敌畏质子化离子峰位于 m/z 223,二级特征离子为m/z 109和127。在优化的条件下,以m/z 127的信号强度为定量指标,建立了蜂蜜中敌敌畏残留的定量检测方法。结果表明,在蜂蜜基质中,敌敌畏在5~1000 ng/mL浓度范围内与m/z 127的信号强度线性关系良好,相关系数为0.998,检出限为1.0 ng/mL(S/N=3);蜂蜜中3个加标水平(10,30和400 ng/mL)的敌敌畏的回收率为93.0％~103.0％,精密度(RSDs)小于4.4％。同时采用气相色谱(火焰光度检测器)方法作为对照方法,检测敌敌畏加标蜂蜜样品,结果表明,加标蜂蜜在5~1000 ng/mL浓度范围内与峰面积线性关系良好,相关系数为0.999,检出限为1.6 ng/mL;10,30和400 ng/mL 3个水平加标蜂蜜的回收率为94.9％~110.3％,精密度小于7.6％。     

超高效液相色谱-串联质谱法快速检测蔬菜中23种植物生长调节剂

建立了超高效液相色谱-串联质谱(UHPLC-MS/MS)快速检测蔬菜中23种植物生长调节剂的分析方法。蔬菜样品采用含1%(体积分数)乙酸的乙腈提取,6 g无水硫酸镁和1 g氯化钠盐析后,无需净化,直接进行UHPLC-MS/MS分析,正负离子同时扫描和多反应监测模式(MRM)检测,基质匹配标准溶液外标法定量。23种植物生长调节剂在各自的浓度范围内线性关系良好,相关系数(r2)均大于0.98。除矮壮素、缩节胺的回收率为50.5%~73.7%,其余21种植物生长调节剂在3个加标水平下的平均回收率为70.2%~125.6%,相对标准偏差(RSD)为0.7%~22.5%,方法定量下限为1~50μg/kg。该方法简单、快速、灵敏、准确,适用于蔬菜样品中23种植物生长调节剂的快速检测。     

质谱快速分析猪肉中痕量沙丁胺醇及克伦特罗

采用内部萃取电喷雾电离质谱( iEESI-MS)技术,在无需样品预处理的前提下,采用标准加入法直接对猪肉组织中沙丁胺醇与克伦特罗进行定性和定量分析。结果表明,本实验对猪肉组织中沙丁胺醇与克伦特罗具有较高的灵敏度,单个样品单一指标的检测时间少于30 s。在0.01~1000μg/kg浓度范围内,信号强度对数(Y)与浓度对数(X)具有较好的线性关系,定量限分别为6.2和9.8 ng/kg。本方法分析速度快、样本耗量少、灵敏度高,适用于猪肉中痕量沙丁胺醇与克伦特罗等“瘦肉精”的快速检测。     

直接进样杆大气压电离源-高分辨质谱法快速检测水果中的乙氧基喹啉残留

将直接进样杆大气压电离源(DIP-APCI)与串联四级杆飞行时间质谱(QTOFMS)联用,无需复杂样品前处理和色谱分离,建立了水果中乙氧基喹啉的快速检测方法。采用等体积进样和内标标准曲线法,提高了常压直接分析质谱的定量准确性,采用多反应监测(MRM)模式扫描,可有效降低基质干扰。该方法在0.1~10μg·mL~(-1)浓度范围内呈线性,相关系数R=0.9991,检测限为0.05mg·kg~(-1),在样品中分别添加0.05、2.0、5.0mg·kg~(-1)浓度水平的乙氧基喹啉,回收率为80%~106%,相对标准偏差为4.2%~8.7%。     

基质标准校正-气相色谱-质谱法同时检测地下水中有机氯农药和多环芳烃

建立了同时检测水中17种有机氯农药和16种多环芳烃的气相色谱质谱分析方法。采用C18固相萃取技术萃取水中的有机氯农药和多环芳烃,分析了产生基质效应的主要原因,对不同基质样品进行了回收率比对试验。结果表明方法检出限(LOD)均低于2.0 ng/L,方法所评估的定量限(LOQ)均低于20.0 ng/L,回收率为70%~130%。     

非衍生化高效液相色谱-串联质谱法快速检测生物体液中草甘膦、草铵膦及代谢物

建立了一种非衍生化高效液相色谱-串联质谱快速检测生物体液中草甘膦、草铵膦及其代谢物等8种极性农药的方法。8种极性农药经Metrosep A Supp 5阴离子色谱柱(150 mm×4.0 mm,5μm)分离,以纯水-200 mmol/L碳酸氢铵溶液(含0.1%氨水)为流动相进行梯度洗脱,负离子多反应监测(MRM)模式进行检测。实验结果表明,8种极性农药在0.5~50 ng/mL范围内线性关系良好(r²>0.99),检出限(S/N≥3)为0.08~0.3 ng/mL,定量下限(S/N≥10)为0.3~1 ng/mL。方法的基质效应为86.5%~106%,目标化合物的回收率为81.5%~114%,日内相对标准偏差(RSD)为0.30%~2.8%,日间RSD为0.50%~5.3%。该方法无需复杂的衍生化过程,简便快速、灵敏度高、稳定性好,适用于生物体液中8种极性农药的检测。     

Desorption sonic spray ionization for (high) voltage-free ambient mass spectrometry

Sonic spray ionization is shown to create a supersonic cloud of charged droplets able to promote efficient desorption and ionization of drugs directly from the surfaces of commercial drug tablets at ambient conditions. Compared with desorption electrospray ionization (DESI), desorption sonic spray ionization (DeSSI) is advantageous since it uses neither heating nor high voltages at the spray capillary. DeSSI therefore provides a more friendly environment in which to perform ambient mass spectrometry (MS). DeSSI-MS is herein evaluated for the analysis of drug tablets, and found to be, in general, as sensitive as DESI-MS. The (high) voltage-free DeSSI method provides, however, cleaner mass spectra with less abundant solvent cluster ions and with enough abundant analyte signal for tandem mass spectrometry (MS/MS). These features may therefore facilitate the DeSSI-MS detection of low molar mass components or impurities, or both. The higher-velocity supersonic DeSSI spray also facilitates matrix penetration thus providing more homogenous sampling and longer lasting ion signals.     

Liquid-phase microextraction and desorption electrospray ionization mass spectrometry for identification and quantification of basic drugs in human urine

Hollow fibre liquid-phase microextraction (LPME) and desorption electrospray ionization mass spectrometry (DESI-MS) were evaluated for the identification and quantification of basic drugs in human urine samples. The selective extraction capabilities of three-phase LPME provided a significant reduction in the matrix effects otherwise observed in direct DESI-MS analysis of urine samples. Aqueous LPME extracts (in 10 mM HCl) were deposited on porous Teflon, dried at room temperature, and the dried spots were then analyzed directly with DESI-MS in full scan mode. Pethidine, diphenhydramine, nortriptyline, and methadone were used as model compounds for identification, and their limits of identification were determined to be 100, 25, 100, and 30 ng/mL, respectively. In a reliability test with 19 spiked urine samples, 100% of the positive samples containing the model drugs in concentrations at or above the limit of identification were identified. Diphenhydramine was used as a model compound for quantitative analysis with diphenhydramine-d(5) as an internal standard. The calibration curve was linear in the range 50-2000 ng/mL (R(2) = 0.992) with a limit of quantification at approximately 140 ng/mL. The intra- and inter-day relative standard deviations were <9.5%. In a reliability test with six spiked urine samples, deviations between the measured and the true values for diphenhydramine were in the range 0.2-22.9%.     

Rapid analysis of svoc in aerosols by desorption electrospray ionization mass spectrometry

Desorption electrospray ionization mass spectrometry (DESI-MS) was applied for the first time to the analysis of semivolatile organic compounds (SVOC) in atmospheric aerosols. We took polycyclic aromatic hydrocarbons (PAHs) as representatives of SVOCs. The DESI-MS conditions were optimized and the limit of detection for PAHs was about 10 pg with 5 s sampling time. PAHs from both laboratory-made biomass burning aerosols and ambient aerosols were selectively and rapidly analyzed without extraction or preconcentration. The observed PAH species and their relative ion intensities are discussed. This work demonstrates that DESI-MS is a promising method for rapid semiquantitative analysis of SVOC in atmospheric aerosols.     

Desorption electrospray ionization mass spectrometry: direct toxicological screening and analysis of illicit Ecstasy tablets

Desorption electrospray ionization mass spectrometry (DESI-MS) was used as a simple and rapid way to analyze drug tablets and powders without sample preparation. Experiments were performed with a home-made DESI source coupled to a triple-quadrupole linear-ion trap (QqQ(LIT)) mass spectrometer. Twenty-one commercial drugs as well as some illicit Ecstasy tablets and powders were analyzed. MS spectra almost exclusively showed the protonated or deprotonated ion of the drug after directing the pneumatically assisted electrospray onto the tablet's surface. With some tablets, inhomogeneity of the surface resulted in different spectra depending on the spot analyzed, thus showing that DESI could be used for imaging. Directly triggered MS/MS spectra were used for confirmatory analysis, with analysis times often below 10 s per tablet. For illicit Ecstasy tablets, DESI-MS, GC/MS and LC/MS analyses provided similar qualitative results for the main analytes. With MS/MS spectra library comparison or exact mass measurements, this technique could become very powerful for the rapid analysis of unknown tablets and shows the great potential of desorption techniques as an alternative to solution-based analysis.     

Simultaneous determination of paracetamol and dextropropoxyphene in human plasma by liquid chromatography/tandem mass spectrometry: application to clinical bioequivalence studies

A liquid chromatography/mass spectrometry method for simultaneous determination of paracetamol and dextropropoxyphene in human plasma is described. Paracetamol and dextropropoxyphene, together with their internal standards (tolbutamide and pyrroliphene), were extracted from 0.5 mL of plasma using solid-phase extraction. The chromatography was performed using a Thermo Hypersil APS-2 Amino column (250 mm x 4.6 mm, 5 microm) with a mobile phase consisting of acetonitrile and 0.4% glacial acetic acid in water (20:80). The total run time was 6 min for each sample. The triple-quadrupole mass spectrometer was operated in both positive (for detection of dextropropoxyphene and its IS pyrroliphene) and negative (for detection of paracetamol and its IS tolbutamide) modes using a polarity-switching technique. Multiple reaction monitoring was used for quantification. The method was linear over the concentration range of 0.1-20 microg/mL for paracetamol and 0.5-80 ng/mL for dextropropoxyphene. The intra- and inter-day precision were less than 10%, and the accuracy ranged from 92.2-110.9%. The lower limits of quantification were 0.1 microg/mL for paracetamol and 0.5 ng/mL for dextropropoxyphene. The present method provides a robust, fast and sensitive analytical tool for both paracetamol and dextropropoxyphene, and has been successfully applied to a clinical bioequivalence study in 14 subjects.     

Development of a novel LC–MS/MS method for detection and quantification of tramadol hydrochloride in presence of some mislabeled drugs: Application to counterfeit study

Counterfeiting of pharmaceuticals has become a serious problem all over the world, particularly in developing countries. In the present work, a highly sensitive LC–MS/MS method was developed for simultaneous determination of tramadol hydrochloride in the presence of some suspected mislabeled drugs such as alprazolam, diazepam, chlorpheniramine maleate, diphenylhydramine and paracetamol. The prepared samples were analyzed on an API 4000 mass spectrometer using an Eclipse C₁₈ column (3.5 μm, 4.6 × 100 mm). The mobile phase consisting of 0.01% formic acid, acetonitrile and methanol (60:20:20 v/v/v) was pumped with an isocratic elution at a flow rate of 0.7 mL min^?1. The detection was achieved on a triple quadruple tandem mass spectrometer in multiple reaction monitoring mode. The proposed method was successfully validated according to International Conference on Harmonization guidelines with respect to accuracy, precision, linearity, limit of detection and limit of quantitation. The calibration linear range for tramadol hydrochloride, alprazolam, diazepam, chlorpheniramine maleate, diphenylhydramine and paracetamol was 5–500 ng mL^?1. The results revealed that the applied method is promising for the differentiation of genuine tramadol tablets from counterfeit ones without prior separation.     

Paracetamol Sensor Based on Molecular Imprinting by Photosensitive Polymers

A voltammetric paracetamol sensor based on molecularly imprinted polymeric (MIP) micelles was prepared by direct electrodeposition. The MIP micelles were prepared via macromolecule self‐assembly of an amphiphilic photocrosslinkable copolymer using paracetamol as the template molecule. The resultant molecularly imprinted polymeric micelles swelled with increasing pH, and the disassociation of the micelles occurred at pH above approximately 7.4. A robust MIP film with good solvent resistance was formed on the electrode surface by anodic electrodeposition of the MIP micelles and subsequent photocrosslinking, resulting in the fabrication of a MIP electrochemical sensor for detecting paracetamol. The resultant sensor showed good response and selectivity towards paracetamol. In addition, a wide linear range from 0.01 mmol/L to 8 mmol/L and a low detection limit of 1×10^?6 mol/L for paracetamol detection was demonstrated based on this sensor. The MIP sensor also showed good stability and reversibility which was applied to determine paracetamol commercial tablets.     

基于敞开式直接电离质谱技术的尿液中毒品检测北大核心CSCD

尿液作为一种易于获取的体内毒品检材,在吸毒人员快速筛查中被广泛应用。针对传统快速筛查技术存在假阳性率高、定量能力不足以及实验室质谱技术在快速检测中存在前处理复杂、检测耗时长、使用环境苛刻等问题,该文提出了一种基于敞开式直接电离质谱技术的生物样本快速检测方法。该研究采用探针式电喷雾离子源与便携式质谱仪联用快速检测平台,优化了喷雾电压和质谱入口毛细管温度,开发了高效快速的前处理技术。基于该平台和前处理技术,5种常规毒品(甲基苯丙胺、氯胺酮、可卡因、O^(6)-单乙酰吗啡和3,4-亚甲双氧甲基苯丙胺)的尿液加标溶液的检出限为0.5~30 ng/mL,且其中4种毒品定量检测的线性相关系数大于0.99。除此之外,5种常规毒品在3个不同水平下的加标回收率为56.1%~103.7%,多次检测结果的相对标准偏差为9.0%~27.8%,说明联用检测平台与前处理方法结合可以达到良好的准确度。为了进一步检验该联用仪器的实战能力,测试了某社区戒毒康复中心40份阳性和110份阴性实际尿液样本,总体检测的准确率接近99%,且通过一次进样在20 s内可同时检测多种毒品。该研究成果有利于推动快速检测技术的发展,促进敞开式直接电离质谱仪技术的推广应用,提升一线执法服务水平。     

电感耦合等离子体发射质谱法测定钨矿石中的钨华

建立电感耦合等离子体发射质谱法测定钨矿石中钨华的含量。用氨水溶液对矿石样品进行浸取分离,将浸取液稀释10倍体积后测定,以3%盐酸溶液作为测定介质。WO3的质量浓度在0~100 ng/m L范围内与信号强度呈良好的线性关系,相关系数为0.999 9,方法检出限为0.5 ng/m L。用该方法对5个钨矿石样品和2个标准物质样品中的钨华进行测定,测定结果的相对标准偏差为2.15%~9.46%(n=12),且与经典方法极谱法测定结果的相对偏差小于10%。该方法快速、简便,精确度较高,可用于钨矿石中钨华的测定。