超高效液相色谱–质谱法测定动物源食品中硝基呋喃类代谢物残留量的方法验证

为提高检测能力,本实验室验证了农业部781号公告-4-2006《动物源食品中硝基呋喃代谢物残留量的测定,高效液相色谱法–串联质谱法》的适用性。本方法验证主要从适用范围、标准曲线、线性、灵敏度、精密度及回收率进行,通过试验发现,本实验室的适用范围标准曲线、线性、灵敏度、精密度及回收率均满足该标准的要求,可以利用该标准对外开展检测业务。

液相色谱-质谱法测定橡胶制品中的福美双

建立了测定橡胶制品中福美双的液相色谱–质谱法。以甲醇为萃取溶剂,对橡胶制品超声萃取,选用ACQUITY UPLC(R)BEH C_(18)色谱柱,用超高效液相色谱–二极管阵列–质谱联用仪对福美双进行检测。在优化的分析条件下,福美双于3 min内获得对称的色谱峰,分离效果良好。福美双的质量浓度在0.5~10 mg/L范围内与其色谱峰面积呈良好的线性关系,相关系数r^2大于0.999,检出限为0.5 mg/L,7次重复性测定结果的相对标准偏差小于4%,样品加标回收率为94.0%~107.9%。该测试方法方便快速,测试结果准确、可靠,满足橡胶制品中福美双的定量测定要求。

液相色谱-质谱法测定运动饮料中9种水溶性维生素

建立液相色谱–质谱法快速测定运动饮料中维生素B_1、维生素B_2、泛酸、维生素B_6、生物素、叶酸、维生素B_(12)、烟酸、烟酰胺9种水溶性维生素的方法。样品用水超声提取后,采用ACQUITY HSS T3液相色谱柱分离,以0.1%甲酸甲醇–0.1%甲酸水溶液为流动相,梯度洗脱,采用质谱多反应监测扫描模式的选择性和特异性定量。9种水溶性维生素的质量浓度与色谱峰面积分别在各自范围内具有良好的线性关系,线性相关系数均大于0.999。当称样量为2.00 g,定容体积为50 mL时,方法检出限为0.025 0～0.062 5μg/g,测定下限为0.10～0.25μg/g。样品的加标回收率为90.0%～102.3%,测定结果的相对标准偏差为0.9%～3.2%(n=7)。该方法简便、快速、准确、灵敏,适用于运动饮料中水溶性维生素的测定。

Determination of 13 preservatives in cosmetics by high performance liquid chromatography and verification by mass spectrometry

A method using high performance liquid chromatography(HPLC)was developed for the s imultaneous determination of 13 preservatives(levulinic acid,p-hydroxyacetophenone,raspberry ketone,p-anisic acid,caprylhydroxamic acid,hydroxyethoxyphenyl butanone,methylisothiazolinone,phenoxyethanol,b e n z oic acid,methylparaben,chlorphenesin,dehydroacetic acid,and 5-bromo-5-nitro-1,3-dioxane)in cosmetics.Different types of samples were ultrasonically extracted by methanol,then the separation of 13 preservatives was carried out on a column of Agilent ZORBAX Eclipse XDB-C18(250 mm×4.6 mm,5μm)by gradient elution at a flow rate of 1.0 mL/min,using 0.1%phosphoric acid solution and acetonitrile as mobile phases.The column temperature was 30℃,and the detection was completed by a diode array detector with the wavelengths at 275,230 and 210 nm.Suspected positive samples were further confirmed by liquid chromatography-tandem mass spectrometry or gas chromatography-mass spectrometry.The linear regression analysis data shows good linearity for 13 preservatives in the respective mass concentration range,with their correlation coefficients(r)greater than 0.9998.The limits of detection(LODs)and limits of quantitation(LOQs)of the method are in the ranges of 0.4-100.0 mg/kg and 1.2-250.0 mg/kg,respectively.At three spiked levels,the average recoveries for 13 target compounds in three kinds of matrix samples are within 84.0%-115.4%,and the relative standard deviations(RSD)are within 0.5%-4.8%(n=6).This method is convenient,efficient,and precise,which can be used for qualitative and quantitative analysis of common preservatives in daily cosmetics.

Extraction Condition Optimization and Identification of Phenols from Lonicerae flos

Polyphenols were obtained from the natural dried Lonicerae flos by ultrasound-assisted extraction with ethanol as the solvent.Single factor experiment and response surface methodology were employed to optimize the extraction conditions.Ultra-performance liquid chromatrography(UPLC)-tandem mass spectrometry(MS/MS)was employed to identify polyphenols based on the plant widely targeted metabolomics database in a qualitative and quantitative manner.The results showed that the optimal extraction conditions for total phenols from Lonicerae flos were ultrasound-assisted extraction with a solid-to-liquid ratio of 10∶1 g/mL and 57%ethanol at 70 W and 60°C for 11 min.The yield of total phenols extracted under the optimal conditions reached 71.08 mg/g.The phenols in Lonicerae flos were mainly chlorogenic acid isomers,and the flavonoids were mainly nobiletin,galuteolin,and homoarbutin.

Determination of Sulfadimidine in Royal Jelly by C_(18)-functionalized Magnetic Silica Nanoparticles Solid Phase Extraction-High Performance Liquid Chromatography-Tandem Mass Spectrometry

[Objective] This study aimed to develop a method of C_18-functionalized magnetic silica nanoparticles solid phase extraction-high performance liquid chro- matography-tandem mass spectrometry for the determination of sulfadimidine in royal jelly. [Method] The royal jelly samples were pretreated by MCX SPE column and C_18-functionalized magnetic silica nanoparticles, and the purified samples were de- tected by HPLC-MS/MS. [Result] The detection method showed a good linear rela- tionship in the range of 5-80 ugkg （r=0.993 1）. The recovery ranges were between 93%- 104% with the relative standard deviations （RSD） below 11.3%. [Conclusion] Combined with automation equipment, the method is simple, fast, time-saving, and easy to real- ize the automation of sulfadimidine in the royal jelly samples before determination.

Quick valence analysis method of vanadium toward accurate toxicity assessment of vanadium-containing hazardous wastes

In order to develop a quick, efficient and sensitive valence analysis method of vanadium(Ⅴ), the highperformance liquid chromatography(HPLC) was utilized to separate and quantify EDTA-complexed Ⅴ(Ⅲ), Ⅴ(Ⅳ) and Ⅴ(Ⅴ) ions. The influence of EDTA, TBAOH, solution pH and organic modifier on retention behavior of V-EDTA complexes was investigated. Complexed Ⅴ(Ⅲ), Ⅴ(Ⅳ) and Ⅴ(Ⅴ) ions can be separated and quantified in 5 min, with detection limits of 0.04 mg/L Ⅴ(Ⅲ), 0.07 mg/L Ⅴ(Ⅳ), and 0.06 mg/L Ⅴ(Ⅴ), respecti vely. The established method is applied to analyzing the hazardous waste of V-Cr-bearing reducing slag and results demonstrate 49.94% of its Ⅴ element to be toxic Ⅴ(Ⅴ). This work opens a new avenue for quick and accurate toxicity assessment of hazardous wastes containing multivalent heavy metals.

Elimination of matrix effects during analysis of perfluorinated acids in solid samples by liquid chromatography tandem mass spectrometry

Matrix effects can significantly hamper the accuracy and precision of the analysis results of perfluorinated acids （PFAs） in environmental solid samples. Several methods, such as standard addition, isotopically labeled internal standards, clean-up of SPE （solid phase extraction） eluents by dispersive graphitized carbon sorbent and substitution of eletrospray ionization （ESI） source by atmosphere pressure photoionization （APPI） source, were demonstrated for elimination of matrix effects in quantitative analysis of PFAs in solid samples. The resuRs indicate that matrix effects can be effectively eliminated by standard addition, but instrumental analysis time will be multiplied. Isotopically labeled internal standards can effectively negate matrix effects of PFAs with the same perfluorocarbon chain length, but is not valid for the other analytes. Although APPI can eliminate matrix effects for all analytes, it is only suitable for analysis of high pollution levels samples. Clean-up of SPE eluents by dispersive graphitized carbon sorbent not only effectively negate the impact of matrix effect, but also avoid frequent clean of the ESI in order to maintain instrumental sensitivity. Therefore, the best method for elimination of matrix effects is the usage of dispersive graphitized carbon sorbent for clean-up of SPE elution.

Study on the basic nitrogen compounds from coal-derived oil

The distillation range analysis and elemental analysis of fractioned direct liquefied oil were conducted. Each fraction of liquefied oil contains some nitrogen compounds. Using the acid extraction method and gas chromatography/mass spectrometry （GC-MS）, the basic nitrogen compounds have been separated and identified. Compared with the nitrogen content of the liquefied oil before and after separation, the basic nitrogen compounds account for more than half of all nitrogen compounds. The basic nitrogen compounds in the light liquefied oil are easily separated, and contain more types of basic nitrogen compounds. The results also show that there are many basic nitrogen compounds in liquefied oil, such as pyrrole, aniline, pyridine, quinoline and so on. However, there are fewer other types of basic nitrogen compounds.

Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Artemisinin in Rat Plasma

Artemisinin is a potent anti-malarial drug isolated from traditional Chinese medicinal herb, Artemisia annua. The objective of this study was to develop and validate a sensitive and specific LC-MS/MS method for the determination of artemisinin in rat plasma using amlodipine as Internal Standard. The method consist of a simple liquid-liquid extraction with methyl tertiary butyl ether （MTBE） with subsequent evaporation of the supernatant to dryness followed by the analysis of the reconstituted sample by LC-MS/？vIS with a Z-spray atmospheric pressure ionization （API） interface in the positive ion-multiple reaction monitoring mode to monitor precursor--〉product ions of m/z 282.70--〉m/z 209.0 for artemisinin and m/z 408.9--〉m/z 237.0 for amlodipine respectively. The method was linear （0.999） over the concentration range of 7.8-2000 ng/mL in rat plasma. The intra and inter-day accuracy were measured to be within 94-104.2% and precision （CV） were all less than 5%. The extraction recovery means for internal standard and all the artemisinin concentrations used were between 82-85%.

Mass Spectrometric Characterization of a Thermolabile Metabolite of Camazepam

Incubation of camazepam [3-(N,N-dimethyl) carbamoyloxy-7-chloro-1- methyl-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one] with rat liver microsomes and cofactors produced a 3-(N-methyl-N-hydroxymethyl) carbamoyloxy derivative as the most abundant metabolite.This metabolite was thermally unstable and was isolated from a metabolite mixture by normal-phase High-Performance Liquid Chromatography.Its struc- ture was established by chemical ionization and ^(252)Cf plasma desorption time-of-flight mass spectral analyses.

Determination of Forechlorfenuron Residue in Fruits and Vegetables by QuEChERS Extraction and HPLC-MS/MS

[Objective] A quick extraction method of QuEChERS-HPLC-MS/MS was established to determine forechlorfenuron in fruits and vegetables. [Method] Fruits and vegetables were extracted with 0.1% acetic acid of acetonitrile solution and pu- rified by QuEChERS, and then forechlorfenuron residues were determined by HPLC- MS/MS. [Result] The limits of detection （LODs） and low determination limit （LOQ） for the forechlorfenuron was 1.0 vg/kg and 5.0 pg/kg in fruits and vegetables, re- spectively. Regression equations of these hormones had a good linear relationship （FF〉0.999） within 2.0-100.0 vg/L. The average recoveries of forechlorfenuron was in the range of 72.0-115. 0% with the coefficients of variation between 1.5% and 9.8% at the spiked levels of 10.0-500.0 μg/kg. [Conclusion] The method can be applied for the determination of the forechlorfenuron in fruits and vegetables.

Quantitative analysis of trace levels of β-ionone in water by liquid-liquidphase extraction-gas chromatography-mass spectrometry(LLE-GC-MS)

A simple and rapid technique based on liquid-liquid extraction coupled to gas chromatography-mass spectrometric detection(LLE-GC-MS) was developed for analysis of taste and odour compound β-ionone in water. Instrument parameters including programmed oven temperature, injection temperature and ion source temperature were evaluated and optimized. Effects of extraction time, ionic strength and p H on the detection efficiency were investigated and optimum conditions were 8 min of extraction time, without Na Cl addition at p H=9. Good linearity(R2=0.9997) was obtained when the linear range was 10-500 μg/L. The recoveries of β-ionone in ultrapure water and tap water samples were 88%-95% and 110%-114%, respectively. The relative standard deviations(RSD) were less than 10%. The method detection limit(MDL) and rejection quality level(RQL) were achieved at1.98 μg/L and 6.53 μg/L, respectively. LLE-GC-MS was demonstrated to be a rapid and convenient method for the determination ofβ-ionone in water samples.

Application of LC-MS based glutathione-trapped reactive metabolites in the discovery of toxicity of traditional Chinese medicine

We summarized the discovery of liquid chromatography mass spectrometry （LC-MS） based glutathione （GSH） capture of reactive metabolites in traditional Chinese medicine （TCM）, which provides scientific basis for further research and clinical application of Chinese medicine toxicity discovery. This dissertation overviews relevant literatures of GSH capture of reactive metabolites in recent years. And then we review the principles and methods of LC-MS based GSH capture of reactive metabolites, as well as the research progress in the discovery of toxicity of TCM including pyrrolizidine alkaloids, furans and quinoid species. The review shows that the representative compounds of TCM includes adonifoline, lasiocarpine, diosbulbin B and safrol are well dctected by LC-MS based GSH capture technique. And the main analytic systems of LC-MS are triple quadrupole and Q-Trap mass spectrometer. Constant neutral loss scan （CNLS）, precursor ion scan （PIS） and multiple reaction monitor （MRM） are main detection methods to monitor the characteristic GSH conjugate fragmentations. The approach of LC-MS based GSH-trapped metabolites has a good application prospect in the discovery of toxic components of TCM.

Removal of Pharmaceutically Active Compounds in Sequencing Batch Reactor

Biological treatment efficiency of six pharmaceutical compounds （acetazolamide, metronidazole, opipramol, piracetam, salicylamide and tinidazole） was evaluated using lab-scale Sequencing Batch Reactor （SBR）. Comparative biological degradation processes of two types of activated sludge from municipal and pharmaceutical industry sewage treatment plants were examined. Three different organic loadings （0.05 g COD/g MLSS.d, 0.1 g COD/g MLSS.d and 0.2 g COD/g MLSS-d） and reaction time on the efficiency of Active Pharmaceutical Ingredient （API） decomposition were examined. Chemical oxygen demand, non-purgeable organic carbon as well as ammonium nitrogen contents were monitored by standard methods. Percentage of API decomposition was analysed by High Performance Liquid Chromatography （HPLC）. The overall API removal efficiency was strictly dependent on the type of activated sludge origin. The main biodegradation products were identified using HPLC-MS,1H NMR and 13C NMR methods as e.g. （{4-[3-（5H-dibenzo[b,f]azepin-5-yl]piperazin-l-yl}methanamine） and （2-amino-1,3,4-thiadiazol-5-sulfonamide） for opipramol and acetazolamide respectively.

Metabolism of pectenotoxins in brown crabs Cancer pagurus fed with blue mussels Mytilus edulis

We investigated the metabolism of pectenotoxins in brown crabs(Cancer pagurus).The crabs were fed with blue mussels(Mytilus edulis) for 21 d then depurated for 42 d.We extracted the toxins from the digestive glands of contaminated crabs,uncontaminated crabs(control group),and the meat of blue mussels using methanol.Extracts of the crab digestive glands were fractionated by liquid-liquid partitioning and solid phase extraction.The fractions were analyzed by liquid chromatography coupled with tandem mass spectrometry(LC-MS/MS) and liquid chromatography coupled with ion-trap mass spectrometry(LC-MSn).We detected a new PTX-like compound,designated as metabolite-1.The MS2 mass spectrum of the metabolite-1 [M+Na]+ ion at m/z 897.5 revealed fragment ions at m/z 853.5 and 555.5,typical of those exhibited by other pectenotoxins.

A method for the quantitative determination of glycyrrhetic acid in plasma by LC-MS/MS and its application in a pharmacokinetic study of ammonium glycyrrhetate

A simple and rapid liquid chromatography-tandem mass spectrometry（LC-MS/MS）method was developed and validated for the quantitative determination of glycyrrhetic acid（GA）,metabolite of glycyrrhizin and glycyrrhetate,in human plasma.GA and internal standard（IS,thiamphenicol）were separated on a C_（18）column by elution with acetonitrile-ammonium acetate solution（5 mmol/L）（70：30,v/v）after a simple liquid-liquid extraction with ethyl acetate.The flow rate was 0.8 mL/min. They were detected by tandem mass spectrometry in the negative ion multiple reaction monitoring（MRM）mode with ion transitions of m/z 469.3→355.3 for GA and m/z 354.1→185.0 for IS.The calibration curve was linear over GA concentration range of 0.5-500 ng/mL（r^20.99）,with intra-and inter-day precisions（RSD）of less than 7.1%,and mean extraction recovery of 74.3%. The method was used for the pharmacokinetic study of ammonium glycyrrhetate after its oral administration of a single dose of 75 mg ammonium glycyrrhetate tablet in humans.The main pharmacokinetic parameters of GA were as follows：AUC_（0-t） （3457.26±1999.01）ng·h/mL;AUC_（0-∞）（3708.85±2428.36）ng·h/mL;MRT_（0-t）（19.69±4.03）h;MRT_（0-∞）（22.83±8.45）h;t_（1/2）Z （11.71±7.77）h;T_（max）（13.40±4.84）h;CLz/F（29.17±19.82）L/h;Vz/F（487.38±518.07）L;C_（max）（215.85±99.88）ng/mL.

HPLC-DAD-MS法测定异丙托溴铵原料药中有关物质

目的建立测定异丙托溴铵原料药中有关物质的高效液相色谱–二极管阵列检测器–质谱(HPLC-DAD-MS)法。方法采用HPLC-MS法,Alltima C_(18)色谱柱(150 mm×4.6 mm,5μm);流动相:0.01 mol/L乙酸铵–乙腈,梯度洗脱;体积流量:0.25 m L/min;柱温:35℃,进样量:10μL;检测波长:220 nm。采用离子阱(ESI)正负离子模式进行检测,源温110℃;脱溶剂温度350℃;脱溶剂气体积流量600 L/h;锥孔气体积流量50 L/h。结果异丙托溴铵、托品酸、托品酸乙酯和杂质F在0.01~10.00、0.012~12.000、0.083~8.300、0.05~5.00 mg/m L显示良好的线性关系;异丙托溴铵、托品酸、托品酸乙酯和杂质F的最低检测限分别为1.46、0.57、4.16、5.03 ng;异丙托溴铵、杂质C、托品酸乙酯和杂质F的定量限分别为4.38、1.71、12.48、15.09 ng。结论该方法灵敏度高、选择性高、检测限低,为异丙托溴铵的质量控制提供依据。

Quantitative determination of ilexgenin A in rat plasma by liquid chromatography coupled with mass spectrometry and its pharmacokinetics

A sensitive and selective high performance liquid chromatography coupled with electrospray ionization mass spectrometry （LC-MS） was developed for the quantitative determination of ilexgenin A （IA）,a major component in Radix Ilicis Pubescentis,in rat plasma.Chromatographic separation was performed on a C 18 column,with methanol-5 mM ammonium acetate （80：20,v/v） as the mobile phase.Mass spectrometer was set in negative mode with target ions at m/z 501.1→501.1 for IA and m/z 779.4→779.4 for digoxin （internal standard,IS）.Rat plasma was extracted with ethyl acetate after addition of phosphoric solution and the organic layer was evaporated and reconstituted with mobile phase for LC-MS analysis.The proposed method was validated with a linear range of 1.05-525.5 ng/mL for IA with limit of quantitation （LOQ） at 1.05 ng/mL.Intra-and inter-day precision expressed as relative standard deviation （RSD） were less than 10% at LOQ level and overall recovery was over 80%.This validated method was used successfully for the pharmacokinetic study of IA in rats after oral dosing of IA （100 mg/kg） and some main pharmacokinetic parameters of IA in rats were obtained.

An UPLC-MS/MS application to investigate the chemical composition of the ethanol extract from Anoectochilus chapaensis and its hypoglycemic activity in insulin-resistant HepG2 cells

Anoectochilus chapaensis Gagnep. （Orchidaceae） was named as the ＂king of medicine＂ because of its excellent efficacy for the treatment of diabetes. However, the bioactive constituents are unknown. An ethanol extract from A. chapaensis showed significant stimulating effect on glucose consumption in HepG2 cells. The chemical composition was investigated by UPLC-MS/MS in negative electrospray ionization （ESI） mode, and 63 compounds including flavonoids, triterpenoids, and aliphatic acids were tentatively identified by accurate mass and characteristic fragments. Moreover, the method of hypoglycemic screening with insulin resistant HepG2 cells and UPLC-MS/MS might be potentially useful in rapid and efficient characterization and primary prediction of natural products prior to traditional isolation.