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.

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).

Chemical Components of Achyranthes bidentata Leaves by Ultra High Performance Liquid Chromatography-Mass Spectrometry

[Objectives] To study the chemical components and relative content of Achyranthes bidentata leaves and provide a scientific basis for further development and utilization of A. bidentata leaves.[Methods] The chemical components of A. bidentata leaves were rapidly analyzed using the ultra high performance liquid chromatography-time of flight-high resolution mass spectrometry (UHPLC-TOF-MS).[Results] Thirty eight chemical compounds were identified in samples of A. bidentata leaves collected from Wen County of Henan Province, in which seven chemical compounds had the relative content higher than 5%, linoleic acid reached 25.7% and inokosterone A reached 13.8%.[Conclusions] A. bidentata leaves contain many kinds of chemical compounds. This study is expected to provide a certain basis for further extraction of linoleic acid and inokosterone A.

Simultaneous Determination of Ultraviolet Absorbers and Antibacterial Agents in Textiles by Ultra-High Performance Liquid Chromatography/Orbitrap High Resolution Mass Spectrometry

This paper reported a new analytical method for the simultaneous determination of seven benzotriazole ultraviolet absorbers and seven antibacterial agents in textiles. After ultrasonic extraction for the textile samples in methanol, the solutions were analyzed by ultra-high performance liquid chromotagraphy/orbitrap high resolution mass spectrometry (UPLC/Orbitrap HRMS). It showed that a good chromatographic separation for these target compounds was achieved by a Hypersil GOLD column (100 mm × 2.1 mm × 1.9 μm) with a gradient elution of methanol and 0.1% aqueous formic acid solution (containing 0.5 mmol/L ammonium acetate). Triclosan and 4-chloro-3,5-dimethyl phenol (PCMX) were detected by the orbitrap HRMS in an electrospray ionization (ESI) negative mode while the other twelve target compounds were detected by orbitrap HRMS in ESI positive mode. Full scan experiment was performed over the range from m/z 100 to m/z 500. These target compounds were routinely detected with mass accuracy below 2 × 10-6 (2 ppm) at the optimized conditions. The results showed that the limits of detection (LODs) were in the range from 0.1 to 0.3 μg/kg. The blank samples were spiked at three levels and their average recoveries varied from 80.5% to 96.3% while the relative standard deviation (RSD) changed from 3.2% to 9.9%. The present method was also applied for the determination of those ultraviolet absorbers and antibacterial agents in the commercial textiles.

Modernization of Chinese herbal compound and the high performance liquid chromatography tandem mass spectrometry (HPLC-MS)

Chinese herbal compound is playing an important role on curing human diseases.And it has been a trend that Chinese herbal compound is being used all over the world in 21 century.However,our Chinese herbal compound is facing serious challenge for the lack of canonical system of quality criterion for Chinese herbal compound so it has been a urgent problem to set up the quality control standards and reveal therapeutic basis of Chinese herbal compound.In order to give full play to the advantages of Chinese herbal compound,modern scientific and technological is used to research of Chinese herbal compound,especially the high performance liquid chromatography tandem mass spectrometry(HPLC-MS),because it is high sensitive,rapid,and obtain more information.It is very necessary that HPLC-MS is uesed to elucidate the effective components of basic substances of Chinese Herbal Compound,and endow traditional Chinese medicine with modern scientific connotation.

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.

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 24 Allergens in Perfume with High Performance Liquid Chromatography Tandem Mass Spectrometry

A method of 24 allergens determination in cosmetics were established with high performance liquid chromatography tandem mass spectrometry. The targeted compounds were extracted with acetonitrile and determined with LC-MS/MS (MRM mode) with external method. The linearity between concentrations and peak area ratio was obtained from 1.0~5.0 mg/L. The limits of detection were 1.0 mg/L for the instrument and 5.0 mg/kg for the method respectively. The LOQ was 15.0 mg/L. The average recoveries of 24 allergens were between 85.9% and 110.0% at spiked levels of 5, 10 and 20 mg/kg with relative standard derivation (RSDs) of 5.5%~12.0%(n=10). The method could be used as a reliable means for simultaneous quantitative determination of allergens in cosmetics.

Development of a Rapid and Simultaneous Detection Method for Buprenorphine, Norbuprenorphine and Naloxone in Human Plasma Using Ultra-high Performance Liquid Chromatography- tandem Mass Spectrometer with Solid-phase Extraction

A simultaneous method was successfully established and validated for the separation and determination of bu- prenorphine （BP）, its primary metabolite, nor-buprenorphine （NBP） and a proposed co-formulate, naloxone （NLX） in human plasma. The method used buprenorphine-d4 （BP-D4）, nor-buprenorphine-d3 （NBP-D3）, naltrexone （NTX） as internal standards （ISs）. 100 μL of plasma sample fortified with the ISs was cleaned up by solid-phase extraction （SPE）, and was then separated on a Waters AcquityTM BEH C18 column with gradient elution using methanol and water （containing 0.2% formic） at a flow rate of 0.25 mL·min^-1. The mass spectrometer was used for detection and was operated in the positive electrospray ionization with multiple reaction monitoring （MRM） mode. The three compounds were effectively separated in 5 min. The linear ranges of the compounds were 0.1--25, 0.25--25 and 0.05--25 ng·mL^-1 for BP, NBP and NLX, respectively, with r≥0.9935. The method had high sensitivity （the lim- its of detection were 0.02, 0.1 and 0.01 ng.mL-1 for BP, NBP and NLX, respectively） and high recoveries （≥97.6%）. The result was shown to be linear and satisfactorily met current acceptance criteria for validation of bio- analytical method： intra and inter assay precisions within the required limits of ≤25% RSD. The LOQs fulfilled the LOQ requirements： precision≤25% RSD, and was fully validated according to the State Food and Drug Administration （SFDA） regulations. The results demonstrated that ultra-high performance liquid chromatography- tandem mass spectrometer （UPLC-MS/MS） with SPE was a powerful detection tool and contributed to pharmaceutical analysis in biological matrices.

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.

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.

Rapid Determination of Tetrodotoxin in Human Plasma by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A sensitive analytical method was developed to determine tetrodotoxin（TTX） in human plasma samples using protein precipitation, followed by ultra performance liquid chromatography（UPLC） analysis coupled with tandem mass spectrometry（MS/MS） using 11-deoxytetrodotoxin（11-deoxyTTX） as an internal standard. The plasma samples were prepared using protein precipitation prior to being analyzed by UPLC-MSfMS to identify TTX over a zwitterionic-hydrophilic interaction liquid chromatography column. The retention time values of TTX and 11-deoxyTTX were 4.12 and 3.67 min, respectively. TTX and 11-deoxyTTX were monitored and quantitated on the basis of their ion transitions for their respective precursor ions to their product ions（i.e., m/z 320.0→162. l for TTX and m/z 304.0→176.0 for 11-deoxyTTX） in the multiple reaction-monitoring mode. The lower limit of quantification of this method was determined to be 0.0199 ug/mL. This method showed good linearity for plasma samples that contained TTX concentrations in the range of 0.0199--1.99 ng/mL. The specificity, precision, accuracy, matrix effect, and stability characteristics of this method were also examined. The intra-assay precision and accuracy ranged from 1.89% to 6.00% and from 92.21% to 100.00%, whereas the inter-assay precision and accuracy ranged from 0.64% to 7.75% and from 99.38% to 101.26%, respectively. This new method therefore represents a rapid, accurate, reliable, and highly sensitive method for the qualitative and quantitative analyses of a trace amount of TTX in human plasma samples.

An Automatic Solid Phase Extraction and Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry for Determination of Seven Microcystins at Ultra-Trace Levels in Surface Water

A method was developed for the detection of seven microcystins(microcystin-LR, RR, YR, LA, LY, LW and LF) in surface water using automatic solid-phase extraction(A-SPE) coupled with ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS). The automated solid-phase extraction system was used to extract microcystins(MCs) from water samples. UPLC-MS/MS was used to determine MCs concentrations in just 5 min. Method detection limits were from 0.3 to 0.9 ng/L, microcystin recoveries ranged from 83.8% to 114%, and the relative standard deviation(RSD) varied from 5.6% to 12.5%. This analytical approach was found to be simple, highly sensitive, accurate, which required little manual operation. Additionally, to validate this analytical method, A-SPE+UPLC-MS/MS was applied to characterize the concentration of MCs in Taihu Lake, Wuxi, China.

Investigations on the degradation of aspartame using high-performance liquid chromatography/tandem mass spectrometry

Aspartame is a widely used sweetener, the long-term safety of which has been controversial ever since it was accepted for human consumption. It is unstable and can produce some harmful degradation products under certain storage conditions. A high-performance liquid chromatography/tandem mass spectrometry method was developed for the simultaneous analysis of aspartame and its four degradation products, including aspartic acid, phenylalanine, aspartyl-phenylalanine and 5-benzyl-3,6- dioxo-2-piperazieacetic acid in water and in diet soft drinks. Aspartame and its four degradation products were quantified by a matrix matched external standard calibration curve with excellent correlation coefficients. The limits of detection were 0.16-5.8 μg/L, which exhibited higher sensitivity than common methods. This method was rapid, sensitive, specific and capable of eliminating matrix interferences. It was also applied to the study of the degradation of aspartame at various pH and temperatures. The results indicated that aspartame was partly degraded under strong acidic or basic conditions and the extent of degradation increased with increasing temperature.

GLOBAL ANALYSIS OF THE METABOLITES OF CURCUMIN IN RATS BY ULTRA PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH QUADRUPOLE TIME OF-FLIGHT TANDEM MASS SPECTROMETRY

Curcumin,a safe natural yellow pigment with a wide range of pharmacological activities,is used both in herbal drugs and as a food coloring agents.Studies have shown that curcumin would suffer from extensive metabolism in vivoand the predominant metabolic pathways are reduction and conjugation.In order to comprehensively study the metabolism and enrich the metabolic profile of cxurcumin in vivo,we carried out this research.A systematic method with highly sensitive UPLC-Q/TOF-MS was established to analyze different biological samples of rats after

联合净化法结合高效液相色谱-串联质谱同时测定鸽蛋中5类24种兽药残留

为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪唑类、喹诺酮类和抗病毒类)经1.0%乙酸乙腈溶液提取,氮气吹干,冷冻过夜后,结合QuEChERS净化和正己烷去脂,采用1 mL 0.1%甲酸水-乙腈溶液(v/v,90∶10)复溶;高效液相色谱-串联质谱测定,内标法定量,采用实际样品建立方法的初步应用。结果显示:24种兽药在2.0~200 ng/mL线性关系良好(R2>0.99),该方法的定量限为2μg/kg,平均回收率为62.2%~117.1%,相对标准偏差4.3%~18.9%;实际样品检出的7种目标化合物与标准方法相比的相对标准偏差为1.34%~5.20%。研究表明,建立的检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法省去固相萃取步骤,成本较低,灵敏高效,回收率优良、重复性稳定,适用于鸽蛋中多类兽药的快速监测分析。

超高效液相色谱-串联质谱法测定发酵乳制品中米酵菌酸和异米酵菌酸

该研究采用液液萃取技术结合超高效液相色谱-串联质谱法对发酵乳制品中的米酵菌酸和异米酵菌酸两种细菌毒素进行监测分析,以防控细菌毒素中毒事件的发生。以发酵乳制品为基质,通过考察提取试剂、净化剂和盐析剂以及仪器参数对两种细菌毒素测定效果的影响,确定前处理条件为采用90%丙酮-1%甲酸溶液涡旋提取,高速离心浓缩,经0.22μm滤膜过滤后进行检测。在最佳条件下,米酵菌酸和异米酵菌酸在1~200 ng/mL范围内线性关系良好,相关系数(r)均大于0.999,检出限分别为0.075、0.11μg/kg,在3个加标水平下的回收率为90.8%~106%,相对标准偏差为0.80%~6.1%。该方法相较于其他方法更高效便捷,且无需前处理净化操作,展现了更佳的提取率、更高的灵敏度及更强的准确性,适用于发酵乳制品尤其是批量样品中米酵菌酸和异米酵菌酸的测定。

液液萃取-超高效液相色谱-串联质谱法同时测定尿液中乌头碱和新乌头碱

建立液液萃取-超高效液相色谱-串联质谱法同时测定尿液中乌头碱和新乌头碱的含量。向尿液样品中加入一定量的萃取溶剂,涡旋,离心,取上层有机相,重复萃取两次,合并萃取液,氮吹至干,再复溶于乙腈中。以乙腈和含0.1%甲酸的2 mmol/L甲酸铵溶液作为流动相,梯度洗脱,采用Acquity BEH C_(18)色谱柱分离,电喷雾离子源正离子方式扫描,多反应监测模式监测,以保留时间和特征离子定性,外标法定量。乌头碱和新乌头碱的质量浓度在1.0~100.0μg/L范围内与其色谱峰面积呈良好的线性关系,相关系数均不小于0.998,方法检出限为0.01μg/L。样品加标平均回收率为99.2%~105.4%,测定结果的相对标准偏差为1.7%~4.1%(n=5)。该方法灵敏度高,准确可靠,适用于食物中毒患者尿液中乌头碱和新乌头碱的检测。

高效液相色谱串联质谱法快速测定鸡蛋中灭蝇胺的残留量

目的:通过研究色谱质谱条件、提取条件等内容,确定快速测定鸡蛋中灭蝇胺残留量的高效液相色谱串联质谱条件。方法:样品经乙腈溶剂超声提取后冷冻,离心后过0.22μm有机滤膜直接上机测试,梯度洗脱,内标校正,外标法定量。结果:方法检出限为0.28μg·kg^(-1),相关系数r=0.9991,平均回收率在97.2%~101.7%,重复测定相对标准偏差小于10%。结论:方法灵敏度高、操作简单、定量准确,是鸡蛋中灭蝇胺含量检测的理想方法。

超高效液相色谱-串联质谱测定胆石症患者血清胆汁酸谱的意义及价值

目的:探究超高效液相色谱-串联质谱测定胆石症患者血清胆汁酸谱的意义及价值。方法:选取2023年7月至12月收治的83例胆石症患者资料进行回顾性分析,并按1∶1比例选取同期体检健康者83例为对照组。比较两组受试者血清初级胆汁酸谱、次级胆汁酸谱差异,分析胆石症影响因素及胆汁酸谱诊断胆石症的价值效能。结果:研究组受试者牛磺胆酸(TCA)、甘氨鹅脱氧胆酸(GCDCA)、甘氨胆酸(GCA)、甘氨熊脱氧胆酸(GUDCA)、牛磺熊去氧胆酸(TUDCA)、牛磺鹅去氧胆酸(TCDCA)高于对照组,差异有统计学意义(P<0.05)。二元Logistic回归分析显示,TCA、GCDCA、GCA、TUDCA、TCDCA均是胆石症发生的危险因素(P<0.05)。ROC曲线分析显示,TCA、GCDCA、GCA、TUDCA、TCDCA诊断胆石症的AUC分别为0.760、0.755、0.914、0.855、0.880,联合数据诊断胆石症的的AUC分别为0.921,敏感度为91.6%,特异度为97.6%。结论:胆石症患者血清胆汁酸谱存在异常,超高效液相色谱-串联质谱测定的血清胆汁酸谱可作为评估胆石症的有效方式之一,为临床早期预防提供参考。