Simultaneous Determination of 14 β-Receptor Agonists Residues in Mutton by High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS)

[Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-glucuronidase and extracted with 5%acetic acid-acetonitrile(1:99,V/V)solution.An Eclipse plus C 18 column was used for separation,and the MRM mode was used for qualitative analysis,and the external standard method was used for quantitative analysis of matrix standard solutions.[Results]Under the optimal conditions,the retention time of the 14 kinds ofβ-receptor agonists ranged from 1.0 to 9.5 min.When the mass concentration was in the range of 0.05-0.50μg/ml,the linear relationship ofβ-receptor agonists was good,with correlation coefficients(r)≥0.9992.The detection limits of the method were in the range of 0.04-0.87μg/kg,and the quantitative limits were in the range of 0.35-1.86μg/kg.The average recovery values were in the range of 82.8%-108.9%,with RSDs(n=6)in the range of 1.9%-6.7%.[Conclusions]The method is simple,sensitive,reproducible,accurate,and can be used for simultaneous determination of the 14 kinds ofβ-receptor agonist residues in mutton.

Detection of 36 antibiotics in coastal waters using high performance liquid chromatography-tandem mass spectrometry

Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems, researchers have often focused on relatively few antibiotics, because of the absence of suitable analytical methods. We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters, including tetracyclines （TCs）, sulfanilamides （SAs）, and quinolones （QLs）. The method consists of solid-phase extraction （SPE） and liquid chromatography-tandem mass spectrometry （LC-MS/MS） analysis, using electrospray ionization （ESI） in positive mode. The SPE was performed with Oasis HLB and Oasis MCX cartridges. Chromatographic separation on a Cr8 column was achieved using a binary eluent containing methanol and water with 0.1% formic acid. Typical recoveries of the analytes ranged from 67.4% to 109.3% at a fortification level of 100 ng/L. The precision of the method, calculated as relative standard deviation （RSD）, was below 14.6% for all the compounds. The limits of detection （LODs） varied from 0.45 pg to 7.97 pg. The method was applied to detemaine the target analytes in coastal waters of the Yellow Sea in Liaoning, China. Among the tested antibiotics, 31 were found in coastal ＇waters, with their concentrations between the LOD and 212.5 ng/L. These data indicate that this method is valid for analysis of antibiotics in coastal waters. The study first reports such a large number of antibiotics along the Yellow Sea coast of Liaoning, and should facilitate future comprehensive evaluation of antibiotics in coastal ecosystems

Determination of okadaic acid related toxins from shellfish (<i>sinonovacula constricta</i>) by high performance liquid chromatography tandem mass spectrometry

Consumption of shellfish contaminated with algal toxins produced by marine dinoflagellates can lead to diarrhetic shellfish poisoning (DSP). It was therefore essential that there are analytical techniques to identify and quantify DSP toxins in shellfish. This new methodology could facilitate DSP monitoring and create a means of rapidly responding to incidents threatening public health. In the last years there were different analytical methods for DSP, such as mouse bioassay and LC-FLD. With the development of instrument, Liquid chromatography-mass spectrometry was substituted for other analytical methods with its good sensitivity and selectivity and without derivatization for the determination of DSP. In this report, a high performance liquid chromatogra-phytandem mass spectrometric(HPLC-MS/MS)method was developed for the simultaneous determination of okadaic acid (OA) and dinophysistoxins(DTX1) in Sinonovacula constricta. Optimization of pretreatment experiment was carried out to maximize recoveries and the effectiveness. The analytes were determined under multi-reactions monitoring (MRM) scan type with tandem mass analyzer using negative ion electrospray ionization (-ESI) mode .Finally, the detection and identification of OA and DTX-1 were based upon their retention times (RT) and the fragmentation patterns of their mass spectra. The method of LOQ for the two poisons was 0.02 mg·kg-1.The real sample test showed that this method could be used for sensitive, fast, and accurate determination of the two diarrheic shellfish poisons in shellfish.

Determination of chlorpromazine in porcine muscle using high performance liquid chromatography-tandem mass spectrometry

A rapid and accurate high performance liquid chromatography tandem mass spectrometry（HPLS-MS） method was established for quantification of chlorpromazine in pork. The porcine samples were pretreated with acetonitrile to precipitate proteins and followed by extraction with tert--butyl methyl ether（TBME）. The separation was performed on a 5 μm Agilent XDB--C18 column with gradient elution. The mobile phase A was 0.01 mol/L ammonium formate in water and mobile phase B was acetonitrile. The flow rate was at 0.8 mL/min. Quantification was performed on a triple-quadrupole tandem mass spectrometer using the multiple selected reaction monitoring（MRM） mode. Transition of m/z ＋319.1 to 58.1 was used for the quantification of chlorpromazine. The method was validated at the concentration range of 0.4040 μg/kg to 8.080 μg/kg for chlorpromazine with correlation coefficient of 0.9999. The spiked recoveries were more than 80.0% and the limit of detection（LOD） was 0.052 μg/kg. The developed method, which offers advantages of convenience, rapid, specificity and higher sensitivity, can be used for determination of chlorpromazine hydrochloride in porcine muscles.

宠物毛发中全氟/多氟化合物的固相萃取/高效液相色谱-串联质谱分析方法研究

该研究对宠物毛发中全氟/多氟化合物(PFAS)的萃取方法进行优化,建立了固相萃取/高效液相色谱-串联质谱(SPE/HPLC-MS/MS)同时测定宠物毛发中包括替代品6∶2氯代多氟醚磺酸(6∶2 Cl-PFESA)和全氟壬烯氧基苯磺酸钠(OBS)在内的24种PFAS的分析方法。样品以乙腈为溶剂超声和振荡萃取2次,萃取液用弱阴离子交换(WAX)固相萃取柱进行净化,收集洗脱液氮吹浓缩后进行HPLC-MS/MS分析。在优化条件下,目标化合物的仪器检出限(LOD)和方法检出限(MDL)分别为0.005~0.136 ng/mL和0.009~0.273 ng/g。24种PFAS的加标回收率为66.2%~110%,相对标准偏差(RSD)为1.5%~21%。采用该方法对52个实际宠物毛发样品进行分析,24种PFAS均被检出,检出率为3.8%~98.1%,PFAS总含量为0.89~17.94 ng/g,平均含量为5.02 ng/g。该方法灵敏度高、稳定性好,应用于宠物毛发中PFAS分析可获得满意的结果。

Detection of Endocrine Disruptors in Water around Landfills

[Objectives]This study was conducted to explore the occurrence levels of endocrine disruptors(EDCs)in rural areas around a county landfill in Tongren City.[Methods]The water around the landfill was sampled and analyzed.A solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)method was established for the determination of 27 EDCs.After the HLB solid-phase extraction column was activated,a water sample,which was adjusted with phosphoric acid to a pH of 2(±0.5)and added with 500 mg of disodium EDTA,was loaded,and 5 ml of water and 20%methanol water was added for washing.Next,10 ml of elution solution was added for elution,and the collected eluate was evaporated under reduced pressure at 40℃to near dryness,and 1 ml of reconstitution solution was added to a constant volume.An ACQUITY UPLC BEH C18(100×2.1 mm,2.6μm)chromatographic column was adopted for LC separation by gradient elution with pure water solution-acetonitrile as the mobile phase.For MS detection,the MRM mode was adopted for collection,and the positive and negative ion modes were switched for simultaneous determination,and the internal standard method was used for quantification.[Results]The correlation coefficient R2 was greater than 0.99 in the linear range of each target substance.The limits of quantitation in the method were between 0.05 and 2.00 ng/L,and the recoveries ranged from 75.3%to 105.7%.[Conclusions]The method has high sensitivity,good accuracy and strong practical value.

Study on Detection of Antibiotic Contents in Water around Landfill Sites

[Objectives] An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established for simultaneous determination of 26 antibiotics in the water around landfills. [Methods] After an HLB solid-phase extraction column was activated, and a water sample, which was adjusted with phosphoric acid to a pH of (2±0.5) and added with 500 mg of disodium EDTA, was loaded, and 5 ml of water and 20% methanol water was added for washing. Next, 10 ml of elution solution was added for elution, and the collected eluate was evaporated under reduced pressure at 40 ℃ to near dryness, and 1 ml of reconstitution solution was added to a constant volume. An ACQUITY UPLC BEH C18 (100 mm×2.1 mm, 2.6 μm) chromatographic column was adopted for LC separation by gradient elution with 0.1% formic acid aqueous solution-acetonitrile as the mobile phase. For MS detection, the MRM mode was adopted for collection, and the positive and negative ion modes were switched for simultaneous determination, and the internal standard method was used for quantification. [Results] The correlation coefficient R2 was greater than 0.99 in the linear range of each target substance. The limits of detection ranged from 0.15 to 3.00 ng/L, and the limits of quantitation were between 0.80 and 10.00 ng/L, and the recoveries ranged from 77.9% to 104.85%. [Conclusions] The method has high sensitivity, good accuracy and strong practical value.

高效液相色谱-串联质谱法对猪肉中四种大环内酯类药物残留量的测定

A simple and sensitive method was developed for the simultaneous determination of four macrolides in pork using high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).Homogenized sample was extracted with NaH2PO4 buffer and acetonitrile solution,and defatted with n-hexane.Further cleanup was performed on a Sep-Pakt C18 solid-phase extraction cartridge.The compounds were determined by LC-MS/MS operated in positive electrospray ionization mode.The limits of detection(LODs) were 0.5 μg/kg.The average recoveries at three spiked concentration levels of 1.0,5.0,10.0 μg/kg were in the range of 70%-110%,with the intra-day RSD of less than 12.9% and inter-day RSD of less than 13.4%.

液相色谱-串联质谱法测定水环境中的十氯酮

建立了分析测定水环境中十氯酮的液相色谱-串联质谱法。水样经液液萃取、净化后，采用 Eclipse plus C18柱（100 mm×2.1 mm，3.5μm）分离，乙腈和水为流动相进行梯度洗脱，在电喷雾负离子多反应监测模式下进行检测，同位素内标法定量。结果表明：采用液相色谱-质谱联用技术，证实了十氯酮在甲醇中以半缩醛的形式存在，而在丙酮/乙腈中以偕二醇的形式存在。由于十氯酮极性较强，在净化时难以洗脱，并且不耐酸，所以不能与其他有机氯农药一起分析。十氯酮在5～100μg / L 范围有良好的线性关系，相关系数 r2=0.999，检出限及定量限分别为0.70 ng / L 和2.8 ng / L；在5、40和100 ng / L 3个浓度添加水平的平均回收率为95.1％～98.9％，相对标准偏差为3.85％～4.72％。本方法具有良好的灵敏度、回收率和重现性，适用于水环境中十氯酮的测定。

高效液相色谱-串联质谱法测定水产品中甲氧苄啶的残留

建立水产品中甲氧苄啶药物残留量测定的高效液相色谱-串联质谱方法。样品选择乙腈提取，用正己烷脱脂，固相萃取柱净化，采用LC-MS/MS选择反应监测（SRM）正离子模式测定进行定性、定量分析。结果表明：甲氧苄啶药物的检出限（LOD）为0.5μg/kg，定量限（LOQ）为1.0μg/kg，检测结果的相对标准偏差为1.78%-5.08%，加标回收率达到77.1%-93.5%。该方法具有比较高的重现性和选择性，在水产品中甲氧苄啶的残留测定中具有很好的应用前景。

雄激素非依赖前列腺癌细胞系代谢组学的初步研究

探讨雄激素依赖性前列腺癌LNCaP细胞系向雄激素非依赖性前列腺癌细胞系(LNCaP-AI和LNCaP-AI+F)转变过程的代谢组学变化,寻找前列腺癌发生雄激素耐药的可能发生机制。利用超高效液相色谱-四极杆-飞行时间质谱,在电喷雾电离源在正离子模式下,采用60%(V/V)甲醇-0.85%(w/V)NH4HCO3溶液在-40℃淬灭,40%(V/V)乙醇-0.8%(w/V)NaCl溶液在-20℃淬灭,提取平行培养3组的细胞内代谢物上清液测定,获得代谢指纹图谱。数据经Masslynx,SIMCA-P 12.0和SPSS软件进行主成分分析(PCA)、偏最小二乘分析判别(PLS-DA)分析、正交校正的偏最小二乘分析判别(OPLS-DA)分析和非参数检验;根据模型变异权重参数(VIP)、S图、载荷矩阵和P值进行筛选不重复且组间变异小的标志物。雄激素依赖到非依赖转变过程中,酰胺类、溶血磷脂酰胆碱、类固醇激素及植物鞘氨醇呈现减少趋势,鞘磷脂呈增加趋势;含高不饱和度脂肪酰基的磷脂酰胆碱(总不饱和度之和大于10)在转变过程中呈现减少的趋势,而含低不饱和度脂肪酰基的磷脂酰胆碱(总不饱和度之和小于4)则呈现增加的趋势。这些代谢标志物的变化,说明在雄激素非依赖性前列腺癌转变过程中与脂质代谢发生异常密切相关。

超高效液相色谱-串联质谱测定营养强化食品中维生素B_(12)的含量

采用固相萃取（solid phase extraction, SPE）柱对样品中维生素B12进行浓缩与净化,提出了一种可灵敏测定营养强化食品中维生素B12含量的超高效液相色谱-串联质谱（ultra high performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS）方法,并通过实验考察了不同固相萃取柱对维生素B12含量测定结果的影响.实验结果表明,采用HLB（hydrophile-lipophile balance number）固相萃取柱进行富集与净化,维生素B12在0.5～100.0μg/L浓度范围内与其响应值呈良好的线性关系,检出限为1.0μg/kg,说明该方法具有分析速度快、灵敏度高、重复性好的优点,适用于对营养强化食品中维生素B12含量的测定.

液相色谱-四极杆飞行时间质谱法筛查猪肉中5类26种药物残留

建立了同时筛查测定猪肉组织中氟喹诺酮类、磺胺类、有机磷类、β-激动剂类、四环素类5类26种药物残留的液相色谱-四极杆飞行时间质谱分析方法.试样采用QuEChERS前处理方法,样品经酸化乙腈-甲醇（1％乙酸,10％甲醇）提取.提取液以C18分散剂和正己烷净化,氮吹浓缩、定容后过滤膜上机检测.液相色谱以甲醇-水（0.1％甲酸）作为流动相梯度洗脱,C18色谱柱分离;高分辨质谱采用正离子模式检测,以二级质谱特征离子定性,以分子离子精确质量数提取色谱峰面积定量.结果表明26种药物的定量下限为0.4～10μg/kg;加标回收率为56.7％～106.2％,相对标准偏差（RSD）为7.7％～15.8％.方法操作简单、快速、高效,可作为猪肉中26种药物残留的快速筛查检测方法.

Pharmacokinetics of oxiracetam and its degraded substance (HOPAA) after oral and intravenous administration in rats

The pharmacokinetics of oxiracetam and its degraded substance(4-hydroxy-2-oxo-1-pyrrolidine acetic acid,HOPAA)after oral and intravenous administration in rats were studied using an established UPLC-MS/MS method.Three groups of rats after an overnight fasted received 10 g/kg(n=6)oxiracetam suspensions orally,and 2 g/kg(n=6)normal or degraded oxiracetam injections intravenously via a caudal tail vein,respectively.Before the pharmacokinetic experiment,a simple safety evaluation testwas conducted on the degraded oxiracetam injections containing 16.16% HOPAA in mice.There was no mortality by a single intravenous dose of 2 g/kg of degraded oxiracetam injections within twoweeks,demonstrating that HOPAA was non-toxic in mice.Following intravenous administration of the normal injections,the plasma concentration-time curves of oxiracetam and HOPAA both showed a rapid elimination phase.The values of t_(1/2)were 3.1±1.5 h for oxiracetamand 0.8±0.2 h for HOPAA,andthemean residencetimes(MRT)were 1.2±0.1h and 0.8±0.1h,respectively.Oxiracetam and HOPAA after intravenous administration of the degraded oxiracetam injections presented elimination patterns similar to those observed in the normal injections.Oral pharmacokinetic results showed that the Tmax was less than 1.5 h for the two analytes,and both had a longer t_(1/2) and MRT than those of intravenous administration.Contents of HOPAA in three groupswere calculated based on AUC_(0-t) values of the two analytes.The quantitative change of HOPAA in vivo was also evaluated by comparing the plasma concentrations of HOPAA and oxiracetamat the same time for every group.Additionally,the values of absolute bioavailability of oxiracetam were about 8.0%and 7.4%calculated by the normal or degraded oxiracetam injections,whichwere far less than the value of 75%reported in literature,indicating the necessity of further study.

Inhibitory effects of HS014 on glutamate release in astrocytes chronically treated with morphine

Previous studies have confirmed that the number of glial fibrillary acidic protein-positive cells significantly increases during morphine tolerance. However, morphine tolerance is reversed with melanocortin receptor antagonists, and analgesic action is enhanced accordingly. However, these mechanisms remain unclear. In the present study, following addition of morphine to Wistar rat spinal cord astrocytes, glutamate levels in the supematant significantly increased （P 〈 0.05）. At 30-120 minutes following addition of intervention agent to spinal cord astrocytes, naloxone significantly increased glutamate release in morphine-tolerant model cells （P 〈 0.05）, while melanocortin receptor antagonist HS014 decreased glutamate release （P 〈 0.05）. Additional naloxone and HS014 to astrocytes significantly decreased glutamate release compared with additional naloxone alone （P 〈 0.01）. Results from the present study demonstrated that glutamate release was increased in spinal cord astrocytes co-cultured with morphine. Naloxone increased glutamate release, and HS014 reduced glutamate release.

UPLC-QTOF/MS Method for Screening and Determination of 59 Non-labeled Components in Veterinary Drug Preparations

[Objectives]This study was conducted to provide an accurate and reliable method for rapid high-throughput screening of veterinary drug preparations.[Methods]For the matrixes of veterinary drug preparations,high-performance liquid chromatography-high resolution quadrupole time-of-flight mass spectrometry(UPLC-QTOF/MS)was used to establish a fast screening method for 59 non-standard components in five categories of antiviral agents,aminoglycosides,quinolones,sulfonamides,and tetracyclines in veterinary drugs.The target drugs were separated by a Waters ACQUITY UPLC HSS T3 chromatographic column(50 mm×2.1 mm,1.8μm),and data were collected in the positive ion mode.Good separation of the 59 drugs was achieved within 7 min.[Results]In the concentration range of 0-100 ng/ml,each drug showed a good linear relationship,and the correlation coefficients were all greater than 0.999.The detection limits of the 59 drugs were in the range of 0.1-0.5 mg/ml,and the recovery under the addition concentration of 5 mg/ml was in the range of 85.2%-103.8%.[Conclusions]The method is fast,simple,accurate,and highly sensitive,and is suitable for high-throughput screening and qualitative identification of non-standard components in veterinary drug preparations.

Determination of Residual Amount of 15 Plant Growth Regulators in Bean Sprouts by HPLC-MS/MS

[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of residues of 15 plant growth regulators(PGRs)in bean sprouts was established using bean sprouts as an experimental material.Samples were extracted with a solution containing 5%acetic acid-acetonitrile(1∶99,V/V),purified with anhydrous magnesium sulfate,and diluted with methanol solvent to constant volume.The solutions were filtered through 0.22μm filtering membrane and the target analytes were separated on a Phenomenex H18 column.The identification of each compound was established by retention time matching along with the accurate mass measurement of the precursor ions and their main fragment ions.The quantification was carried out using matrix-matched external standard method.[Results]The retention time of the 15 PGRs were found in the range from 5.8-11.7 min under the optimized conditions.The linear relation was good in the concentration range of 0.005-0.050μg/ml,and the correlation coefficients of the 15 PGRs were≥0.9990.The limits of detection were in the range of 0.03-0.92 g/kg,and the limits of quantification were in the range of 0.50-2.10μg/kg.The average recovery in the recovery test at 3 concentration levels was 80%-110%,and the relative standard deviations were in the range of 2.8%-7.5%.[Conclusions]This method is simple and accurate,and can quickly qualitatively and quantitatively analyze the residues of 15 PGRs in bean sprouts.The proposed procedure was simple,quick and accurate for the simultaneous determination of the 15 PGRs in bean sprout.

TLC-HPLC-MS法检测消喘灵中非法掺入的地西泮和醋酸泼尼松

【目的】建立消喘灵中非法添加化学成分地西泮和醋酸泼尼松的定性检测方法。【方法】采用TLC法对怀疑掺有地西泮和醋酸泼尼松的消喘灵的提取物进行初步分离,再通过HPLC-DAD法及MS法对其进行定性。【结果】供试品中分别检测到化学成分地西泮和醋酸泼尼松。【结论】本研究提供的方法可检出中药制剂中非法掺入的化学成分地西泮和醋酸泼尼松,为药监、药检部门提供参考。