Determination of paralytic shellfish poisoning toxins by high-performance ion-exchange chromatography

An efficient LC method has been developed for the determination of paralytic shellfish poisoning (PSP) toxins based on ion-exchange chromatographic separation of the toxins followed by electrochemical post-column oxidation and fluorescence detection as well as mass spectrometric (MS) detection. The method can be applied to the determination of PSP toxins in phytoplankton and to control seafood for PSP content.     

Hydrophilic interaction liquid chromatography--mass spectrometry for the analysis of paralytic shellfish poisoning (PSP) toxins

Hydrophilic interaction liquid chromatography (HILIC) was examined for the separation of paralytic shellfish poisoning (PSP) toxins using the stationary phase TSK-gel Amide-80. The parameters tested included type of organic modifier and percentage in the mobile phase, buffer concentration, pH, flow rate and column temperature. Using mass spectrometric (MS) detection, the HILIC column allowed the determination of all the major PSP toxins in one 30 min analysis with a high degree of selectivity and sensitivity. The high percentage of organic modifier in the mobile phase and the omission of ion pairing reagents, both favored in HILIC, provided limits of detection (LOD) in the range 50-100 nM in selected ion monitoring (SIM) mode on a single quadrupole LC-MS system. LOD in selected reaction monitoring (SRM) mode on a sensitive triple quadrupole system were as low as 5-30 nM. Excellent linearity of response was observed.     

Analysis of paralytic shellfish poisons by capillary electrophoresis

A capillary electrophoresis (CE) method with UV detection is described for the separation and determination of underivatized toxins associated with paralytic shellfish poisoning (PSP). Confirmation of the electrophoretic peaks was facilitated by mass spectrometric (MS) detection using an ionspray CE-MS interface and by high-performance liquid chromatography with fluorescence detection. The determination of PSP toxins, such as saxitoxin and neosaxitoxin, in toxic dinoflagellates and scallops is demonstrated and comparisons are made with existing techniques.     

Rapid detection of cyanobacterial toxins in precursor ion mode by liquid chromatography tandem mass spectrometry

We established an analytical method based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in the precursor ion mode for simultaneous qualitative monitoring of various groups of cyanobacterial toxins. The toxin groups investigated were paralytic shellfish poisoning (PSP) toxins, anatoxins (ANAs), cylindrospermopsins (CYNs), microcystins (MCs), and nodularins (NODs), including rare and uncharacterized derivatives found in plankton and water matrices. Alternative analytical methods based on tandem mass spectrometry commonly operate in multiple reaction monitoring (MRM) mode and depend on prior knowledge of putative toxigenicity of the cyanobacterium species and strain, and the expected toxin variants. In contrast, the precursor ion mode yields diagnostic mass fragments for the detection of characteristic compounds of the different toxin classes and thus allows monitoring of a large set of unspecified cyanotoxins of various groups, even when the species composition is undetermined or uncertain. This rapid method enables screening for a wide spectrum of toxic cyanobacterial metabolites and degradation products in a single chromatographic separation with detection limits at nanogram levels. The precursor ion technique is a valuable adjunct to existing mass spectrometric methods for cyanotoxins, although it is not a complete replacement for detailed quantitative analysis requiring comprehensive sample cleanup.     

Liquid chromatography-tandem mass spectrometric method for determination of the anti-inflammatory compound vicenin-2 in the leaves of L. ericoides Mart

This paper reports a rapid and sensitive method for determination of the anti-inflammatory compound vicenin-2 in L. ericoides Mart. using liquid chromatography-tandem mass spectrometry. Separation of the compound of interest was performed on a VP-ODS(18) (150 x 2 mm, Shimadzu, Japan) column and a pre-column packed with GPV-ODS C(18) (5 x 2 mm, Sigma-Aldrich, USA) with acetonitrile-water (15:85) mobile phase containing 2% acetic acid using isocratic flow at 0.5 mL/min for 2 min. Multiple-reaction monitoring of vicenin-2 was performed using electrospray positive ionization. The linear calibration curves were generated using a concentration range of 5-2500 ng/mL with correlation coefficients >0.99. The values of limit of detection and limit of quantitation were found to be 1 and 5 ng/mL, respectively. The method developed based on LC-ESIMS/MS is advantageous because it permits the rapid and selective detection of vicenin-2. Furthermore, the method can be easily applied to the routine analysis of vicenin-2 in plant extracts using a minimal amount of sample.     

Rapid liquid chromatography-tandem mass spectrometry method for quantification of ziprasidone in human plasma

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of ziprasidone (ZIP) in human plasma was developed. ZIP and N-methyl ziprasidone as internal standard (IS) were extracted from alkalinized plasma using tert- butyl methyl ether. Separation was performed isocratically on a C8 column with 90% acetonitrile containing 2 mmol/L ammonium acetate as a mobile phase with a total run time of 2.5 min. MS/MS transitions of m/z 413 --> 194 and m/z 427 --> 177 of the analyte and internal standard were used for quantification. Confirmatory ions of m/z 413 --> 177 and m/z 427 --> 180 were collected as well. The calibration curve based on peak-area ratio was linear up to at least 200 ng/mL with a detection limit of 0.1 ng/mL. The method showed satisfactory reproducibility with a coefficient of variation of less than 5%. The method was successfully applied to the analysis of ZIP in spiked human plasma.     

在线液相色谱-二极管阵列检测器-串联质谱法检测野生菌中鹅膏毒肽和鬼笔毒肽

建立了在线液相色谱-二极管阵列检测器-串联质谱技术(LC-DAD-MS/MS)同时测定野生菌中多肽类蘑菇毒素(鹅膏毒肽和鬼笔毒肽)的分析方法。样品经甲醇提取,水稀释后,在碱性条件下用XBridge~(TM) BEH C_(18)柱(150m m×3.0 m m,2.5μm)分离,并先后用DAD和MS/MS检测。使用碱性流动相能够实现5种多肽类蘑菇毒素在15 m in内达到基线分离,同时又能有效抑制质谱加钠峰[M+Na]~+的响应信号,保证检测的稳定性和灵敏度。5种蘑菇毒素在0.05~500 mg/kg范围内线性关系良好,相关系数(r)0.99;检出限为0.005~0.02 mg/kg。通过实际样品检测,证明该法操作简单、快速,灵敏度高,宽的定量检测线性范围能满足实际样品中蘑菇毒素含量变化大的特点。     

固相萃取-超高效液相色谱-串联质谱法检测婴幼儿奶粉中的7种链格孢霉毒素

婴幼儿奶粉配料中的植物油易受到链格孢霉菌污染,因而链格孢霉毒素(ATs)成为该类食品的重点检测对象.该研究建立了超高效液相色谱-串联质谱法快速检测婴幼儿奶粉中链格孢酚、链孢酚单甲醚、交链孢霉烯、细交链孢菌酮酸、腾毒素、交链孢毒素Ⅰ、细格菌素7种ATs的方法.通过参数优化确定最佳的质谱与色谱条件,选取BEH-C18色谱柱...     

Determination of lovastatin in human plasma by ultra-performance liquid chromatography/electrospray ionization tandem mass spectrometry

A fast and sensitive ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of lovastatin in human plasma. With simvastatin as internal standard, sample pretreatment involved one-step extraction with n-hexane-methylene dichloride-isopropanol (20:10:1, v/v/v) of 0.5 mL plasma. Chromatographic separation was carried out on an Acquity UPLC BEH C(18) column with mobile phase consisting of acetonitrile-water (containing 5 mmol/L ammonium acetate; 85:15, v/v) at a flow-rate of 0.35 mL/min. The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) via electrospray ionization source with positive mode. The analysis time was shorter than 1.7 min per sample. The standard curve was linear (r2>or=0.99) over the concentration range 0.025-50.0 ng/mL with a lower limit of quantification of 0.025 ng/mL. The intra- and inter-day precision values were below 11% and the accuracy (relative error) was within 6.0% at three quality control levels. This is the first method of MS with MRM coupled to UPLC for the determination of lovastatin, which showed great advantages of high sensitivity, selectivity and high sample throughput. It was fully validated and successfully applied to the pharmacokinetic study of lovastatin tablets in healthy Chinese male volunteers after oral administration.     

盘式固相萃取–超高效液相色谱–串联质谱法快速测定环境水样中3种微囊藻毒素

建立盘式固相萃取–超高效液相色谱–串联质谱(UPLC–MS–MS)快速测定环境水样中3种微囊藻毒素(MCs)的方法。环境水样经过盘式固相萃取柱净化,采用Waters BEH C_(18)色谱小柱,以乙腈–0.2%甲酸水溶液为流动相,梯度洗脱分离后,UPLC–MS–MS多级监测正离子模式下外标法进行定性定量分析。3种微囊藻毒素在0.05~10.0μg/L范围内呈现良好线性关系,相关系数均大于0.999 4,方法检出限为0.02 ng/L。对同一环境样品进行0.1,1.0,5.0μg/L 3种浓度的加标回收试验,平均回收率为82.8%~108.8%,测定结果的相对标准偏差为2.1%~10.1%(n=6)。该方法快速、灵敏、准确,可有效应用于环境水样中微囊藻毒素的监测。     

TurboFlow在线净化-液相色谱-串联质谱法快速检测人尿中鹅膏肽类毒素

鹅膏肽类毒素是一类环状多肽类蘑菇毒素,中毒后会造成急性肝损伤,病死率非常高。我国因误食野生毒蘑菇导致的中毒事件常有发生,测定人尿中鹅膏肽类毒素的浓度,可为临床早期诊断和救治提供有价值的信息。该研究建立了TurboFlow (TF)在线净化-液相色谱-三重四极杆质谱快速定量检测尿液中5种鹅膏肽类毒素(α-鹅膏毒肽、β-鹅膏毒肽、γ-鹅膏毒肽、羧基二羟鬼笔毒肽和二羟鬼笔毒肽)的新方法。尿液样品经高速离心后,直接注入TurboFlow在线净化-液相色谱-串联质谱进行分析。对影响TF在线净化的参数如TF净化柱、上样溶剂、洗脱溶剂、转移流速、转移时间等进行了优化。在优化后的实验条件下,以TurboFlow^TMCyclone柱(50 mm×0.5 mm)为净化柱,Hypersil GOLD C₁₈柱(100 mm×2.1 mm)为分析柱,甲醇和4 mmol/L乙酸铵为流动相进行梯度洗脱,电喷雾正离子选择反应监测(SRM)模式下进行检测,基质匹配外标法定量。结果表明,鹅膏肽类毒素在1.0~50.0 μg/L范围内呈现良好的线性关系,相关系数均可达到0.997以上。方法的检出限为0.15~0.3 μg/L,定量限为0.5~1.0 μg/L。在2.0、5.0和10.0 μg/L的加标水平下,5种鹅膏肽类毒素的日内和日间回收率分别为87.0%~108.6%和86.8%~112.7%,日内、日间相对标准偏差(RSD)均小于14.5%。该检测方法准确、快速、灵敏度高、易操作,适用于公共卫生应急检测或临床中毒病因识别检测。     

Determination of L‐trantinterol in rat plasma by using chiral liquid chromatography‐tandem mass spectrometry

A simple, sensitive, and rapid method for determination of L‐trantinterol in rat plasma was developed for the first time by using LC coupled to MS/MS based on chiral stationary phase. A baseline separation of the enantiomers of trantinterol was achieved on a Chirobiotic V column, using a mixture of acetonitrile–methanol–ammonia–acetic acid (80:20:0.01:0.02, v/v/v/v) as the mobile phase. The detection was performed on a triple‐quadrupole tandem mass spectrometer by multiple reaction monitoring mode via ESI. The calibration curve was linear in concentration range from 0.270 to 108 ng/mL in plasma with the lower limit of quantification of 0.270 ng/mL. The intra‐ and interday precision (relative standard deviation) values were within 10.9% and the accuracy (relative error) was from 2.6 to 9.2% at all quality control levels. The method has been successfully applied to a study of L‐trantinterol pharmacokinetics in rats.     

Determination of acyclovir in horse plasma and body fluids by high-performance liquid chromatography combined with fluorescence detection and heated electrospray ionization tandem mass spectrometry

Two methods are presented for the determination of 'respectively' the plasma protein unbound and total concentration of acyclovir in horse plasma and body fluids: first, a liquid-liquid extraction was performed on plasma, combined with HPLC-fluorescence detection for the total plasma concentration; second a more sensitive method using high-performance liquid chromatography combined with heated electrospray ionization tandem mass spectrometry (LC-HESI-MS/MS) was described for plasma and for body fluids analysis. To obtain the unbound concentration of acyclovir in plasma, a simple deproteinization step using a Microcon filter was performed. Ganciclovir was used as an internal standard. Analysis was carried out on an Inertsil 5 ODS-3 column for the HPLC-fluorescence method. For the LC-HESI-MS/MS method a PLRP-S column was used. The limit of quantification (LOQ) for the total concentration was set at 50 and 2 ng mL(-1) for the HPLC-fluorescence method and the LC-HESI-MS/MS method, respectively. The limit of quantification for the unbound concentration was set at 5 ng mL(-1) and at 2 ng mL(-1) for body fluids. The methods were successfully used to perform pharmacokinetic and clinical studies in horses after intravenous and oral dosage of acyclovir and its prodrug valacyclovir.     

超高效液相色谱-串联质谱法测定血浆与尿液中14种麻痹性贝类毒素北大核心CSCD

人体生物基质中麻痹性贝类毒素的检测对其引起的食物中毒诊断和救治具有重要意义。研究建立了超高效液相色谱-串联质谱法测定血浆、尿液中14种麻痹性贝类毒素的分析方法。实验比较了不同固相萃取柱的影响,优化了前处理条件和色谱条件,血浆样品采用0.2 mL水、0.4 mL甲醇、0.6 mL乙腈提取后直接上机测定,尿液样品采用0.2 mL水、0.4 mL甲醇、0.6 mL乙腈提取,聚酰胺(PA)固相萃取柱净化后上机测定。采用Poroshell 120 HILIC-Z色谱柱(100 mm×2.1 mm,2.7μm)对14种贝类毒素进行分离,流动相为含0.1%(v/v)甲酸的5 mmoL/L甲酸铵缓冲溶液和0.1%(v/v)甲酸乙腈溶液,流速为0.50 mL/min。在电喷雾模式(ESI)下进行正负离子扫描,采用多反应监测(MRM)模式检测,外标法定量。结果表明,对于血浆和尿液样品,14种贝类毒素分别在0.24~84.06 ng/mL范围内线性关系良好,相关系数均大于0.995。尿液检测的定量限为4.80~34.40 ng/mL,血浆检测的定量限为1.68~12.04 ng/mL。尿液和血浆样品在1、2和10倍定量限加标水平下平均回收率为70.4%~123.4%,日内精密度为2.3%~19.1%,日间精密度为4.0%~16.2%。应用建立的方法对腹腔注射14种贝类毒素小鼠血浆和尿液进行测定,20份血浆样本中检出含量分别为19.40~55.60μg/L和8.75~13.86μg/L。该方法操作简便,样品取样量少,方法灵敏度高,适用于血浆和尿液中麻痹性贝类毒素的快速检测。     

超高效液相色谱–串联质谱法测定生活饮用水中10种农药残留

采用超高效液相色谱–串联质谱法测定生活饮用水中10种农药残留。水样直接进样,选用Waters ACQUITY UPLC~BEH C_(18)柱分离,以乙腈–0.1%甲酸溶液为流动相进行梯度洗脱,质谱选用多反应监测模式分析,10种农药的质量浓度在0.5~50μg/L范围内与色谱峰面积呈线性相关,检出限(3S/N)在0.03~0.50μg/L之间,测定值的相对标准偏差在1.14%~9.91%之间,加标回收率在91.6%~107.1%之间。该法简便准确,适用于生活饮用水中农药残留的检测。     

Determination of faropenem in human plasma and urine by liquid chromatography-tandem mass spectrometry

A simple, rapid and sensitive liquid chromatography/electrospray tandem mass spectrometry (LC-MS/MS) quantitative detection method, using cefalexin as internal standard, was developed for the analysis of faropenem in human plasma and urine. After precipitation of the plasma proteins with acetonitrile, the analytes were separated on a C18 reversed-phase column with 0.1% formic acid-methanol (45:55, v/v) and detected by electrospray ionization mass spectrometry in positive multiple reaction monitoring mode. Calibration curves with good linearities (r=0.9991 for plasma sample and r=0.9993 for urine sample) were obtained in the range 5-4000 ng/mL for faropenem. The limit of detection was 5 ng/mL. Recoveries were around 90% for the extraction from human plasma, and good precision and accuracy were achieved. This method is feasible for the evaluation of pharmacokinetic profiles of faropenem in humans, and to our knowledge, it is the first time the pharmacokinetic of faropenem has been elucidated in vivo using LC-MS/MS.     

超高效液相色谱-串联质谱法同时测定浓缩苹果汁中的4种链格孢霉毒素

建立了浓缩苹果汁中链格孢霉素、链格孢酚、腾毒素、链格孢酚甲醚4种毒素残留量的固相萃取-超高效液相色谱-串联质谱检测方法。样品用水稀释后,用PS DVB固相萃取柱净化,外标法定量。测定时用BEH C18色谱柱(50 mm×2.1 mm, 1.7 μm)分离,乙腈和水梯度洗脱,质谱测定采用多反应监测(MRM)模式。4种链格孢霉毒素的测定低限在1.0～5.0 μg/L范围内,加标回收率为77.8%～117.2%,相对标准偏差均低于9.7%。该方法灵敏、稳定、可靠,可用于浓缩苹果汁样品中4种链格孢霉毒素的检测和确证。     

Identification and determination of the major constituents in Kai‐Xin‐San by UPLC‐Q/TOF MS and UFLC‐MS/MS method

In order to have overall chemical material information of Kai‐Xin‐San (KXS), the reliable ultra‐high‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometer (UHPLC–Q‐TOF‐MS) and ultra‐fast liquid chromatography mass spectrometer (UFLC‐MS/MS) methods were developed for the identification and determination of the major constituents in KXS. Moreover, the UHPLC–Q‐TOF‐MS method was also applied to screen for multiple absorbed components in rat plasma after oral administration of KXS. The UHPLC–Q‐TOF‐MS method was achieved on Agilent 6520 Q‐TOF mass and operated in the negative ion mode. Good separation was performed on a ZORBAX Eclipse Plus C18 column with a gradient elution at a flow rate of 0.2 ml/min. A total of 92 compounds in KXS were identified or tentatively characterized based on their exact molecular weights, fragmentation patterns, and literature data. A total of 26 compounds including 23 prototype components and three metabolites were identified in rat plasma after oral administration of KXS. Then, 16 major bioactive constituents were chosen as the benchmark substances to evaluate the quality of KXS. Their quantitative analyses were performed by a triple quadrupole tandem mass spectrometer (MS/MS) operating in multiple‐reaction monitoring mode(MRM). The analysis was completed with a gradient elution at a flow rate of 0.4 ml/min within 35 min. The simple and fast method was validated and showed good linearity, precision, and recovery. Furthermore, the method was successful applied for the determination of 16 compounds in KXS. All results would provide essential data for identification and quality control of active chemical constituents in KXS. Copyright © 2016 John Wiley & Sons, Ltd.     

Selective and sensitive determination of bis(7)-tacrine, a high erythrocyte binding acetylcholinesterase inhibitor, in rat plasma by high-performance liquid chromatography-tandem mass spectrometry

The current study aims to develop a specific and sensitive LC-MS/MS method for determination of bis(7)-tacrine (B7T) in rat plasma. A 100 microL plasma sample was extracted with ethyl acetate. B7T and the internal standard (IS), pimozide, in the samples were then analyzed with LC-MS/MS in positive electrospray ionization condition. Chromatographic separation of B7T and IS was achieved in a C(18) reversed-phase HPLC column (150 x 2.1 mm i.d.) by isocratic elution with a mobile phase consisting of 0.05% formic acid in water and acetonitrile (1:1, v/v) at a flow rate of 0.35 mL/min. Multiple-reaction monitoring (MRM) mode was employed to measure the ion transitions: m/z 247 to 197 for B7T and m/z 462 to m/z 328 for IS, respectively. The method was linear over the studied ranges of 100-5000 and 10-100 ng/mL. The intra-day and inter-day variations of the analysis were less than 6.8% with standard errors less than 9.0%. The detection limit of B7T in rat plasma was 1 ng/mL. The developed method was successfully applied to the pharmacokinetic study of B7T after intravenous administration of 1 mg/kg B7T and further proved to be readily utilized for determination of B7T in rat plasma samples.