顶空固相微萃取/气相色谱-质谱联用测定水中6种挥发性硅氧烷

建立了水中4种环形和2种线形硅氧烷的顶空固相微萃取/气相色谱-质谱联用分析方法.考察了萃取纤维、萃取温度、萃取时间、水样pH值、解析时间、盐效应等因素对实验结果的影响.优化后的条件为:40mL水、40 μL内标(M4Q,500 μg/L)、NaCl(0.1 g/mL)加入60 mL顶空瓶中,选用65μm聚二甲基硅氧烷-二乙烯基苯(PDMS/DVB)纤维于24℃顶空萃取45 min.萃取完成后将纤维插入气相色谱进样口,于200℃解吸2 min进行定性、定量分析.结果表明,6种目标物的方法检出限为(LOD)2.6～7.8 ng/L,回收率为82％～ 96％,相对标准偏差(RSD)为1.1％～7.9％.     

HS-SPME/GC-MS结合化学计量学分析不同产地路路通中的挥发性成分

采用顶空固相微萃取结合气相色谱-质谱技术(HS-SPME/GC-MS)分析了不同产地路路通中的挥发性成分,采用正交试验设计优化了影响顶空固相微萃取技术的各项因素,以主成分分析、聚类分析两种化学计量学方法分析评价了8个产地路路通的挥发性成分。优化实验结果为1 g样品量在80℃下提取40 min,解析1 min。8个产地的路路通共鉴定出48种挥发性组分,不同产地的化学成分大致相同,含量差异较大。两种统计分析方法均表明,湖南、江苏、四川、辽宁4个产地的路路通挥发性成分比较相似,贵州、广西、安徽、河北4个产地的路路通比较接近。主成分分析结果表明,氧化石竹烯、δ-杜松烯、橙花叔醇可作为区分两大类路路通的代表性化合物。HS-SPME/GC-MS结合化学计量学方法可以有效地对不同产地的路路通进行质量评价,从而为中药路路通的药物开发和科学栽培管理提供重要参考。     

Optimization of HS-SPME for GC-MS Analysis and Its Application in Characterization of Volatile Compounds in Sweet Potato

Volatile compounds are the main chemical species determining the characteristic aroma of food. A procedure based on headspace solid-phase microextraction (HP-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) was developed to investigate the volatile compounds of sweet potato. The experimental conditions (fiber coating, incubation temperature and time, extraction time) were optimized for the extraction of volatile compounds from sweet potato. The samples incubated at 80 °C for 30 min and extracted at 80 °C by the fiber with a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) coating for 30 min gave the most effective extraction of the analytes. The optimized method was applied to study the volatile profile of four sweet potato cultivars (Anna, Jieshu95-16, Ayamursaki, and Shuangzai) with different aroma. In total, 68 compounds were identified and the dominants were aldehydes, followed by alcohols, ketones, and terpenes. Significant differences were observed among the volatile profile of four cultivars. Furthermore, each cultivar was characterized by different compounds with typical flavor. The results substantiated that the optimized HS-SPME GC-MS method could provide an efficient and convenient approach to study the flavor characteristics of sweet potato. This is the basis for studying the key aroma-active compounds and selecting odor-rich accessions, which will help in the targeted improvement of sweet potato flavor in breeding.     

Multivariate analysis for the classification and differentiation of Madeira wines according to main grape varieties

In order to differentiate and characterize Madeira wines according to main grape varieties, the volatile composition (higher alcohols, fatty acids, ethyl esters and carbonyl compounds) was determined for 36 monovarietal Madeira wine samples elaborated from Boal, Malvazia, Sercial and Verdelho white grape varieties. The study was carried out by headspace solid-phase microextraction technique (HS-SPME), in dynamic mode, coupled with gas chromatography–mass spectrometry (GC–MS). Corrected peak area data for 42 analytes from the above mentioned chemical groups was used for statistical purposes. Principal component analysis (PCA) was applied in order to determine the main sources of variability present in the data sets and to establish the relation between samples (objects) and volatile compounds (variables). The data obtained by GC–MS shows that the most important contributions to the differentiation of Boal wines are benzyl alcohol and (E)-hex-3-en-1-ol. Ethyl octadecanoate, (Z)-hex-3-en-1-ol and benzoic acid are the major contributions in Malvazia wines and 2-methylpropan-1-ol is associated to Sercial wines. Verdelho wines are most correlated with 5-(ethoxymethyl)-furfural, nonanone and cis-9-ethyldecenoate. A 96.4% of prediction ability was obtained by the application of stepwise linear discriminant analysis (SLDA) using the 19 variables that maximise the variance of the initial data set.     

GC-MS与HPLC/DAD联用对纺织品中4-氨基偶氮苯的测定

从化学反应条件的控制及气相色谱-质谱(GC-MS)和高效液相色谱/二极管阵列检测器(HPLC/DAD)联用方面,探讨了4-氨基偶氮苯的检测方法。实验表明,在样品中加入氢氧化钠,样品中的4-氨基偶氮苯和新鲜配制的连二亚硫酸钠发生反应,使4-氨基偶氮苯的碳碳双键断裂。释放的4-氨基偶氮苯在氯化钠存在的混合物中与叔丁基甲醚进行液液萃取。取叔丁基甲醚层进行分析,通过GC-MS的保留时间及特征离子碎片并结合HPLC/DAD紫外法对4-氨基偶氮苯进行定性和定量分析。4-氨基偶氮苯在2.5~30 mg/kg范围内呈良好的线性关系,其线性方程为:y=91.23x+5.272,相关系数r=1.000,检出限为3.20 mg/kg,平均回收率不低于90%。     

麻黄-甘草药对配伍过程中的主要药效成分的分析

利用高效液相色谱串联质谱联用法(HPLC-MS/MS)和气相色谱质谱联用法(GC-MS)分析了麻黄与甘草药对配伍前后水煎液中主要药效成分的变化,并通过小鼠的耳廓肿胀试验考察了甘草、麻黄单煎液及药对共煎液的抗炎活性变化。分别通过HPLC法和GC-MS法对甘草与麻黄中主要化学成分,甘草酸、甘草苷、麻黄碱和甲基麻黄碱进行了定量分析,通过单煎液和药对共煎液的对比,发现麻黄与甘草配伍共煎液中麻黄碱（含伪麻黄碱）的含量增加了14.52%;甲基麻黄碱（含甲基伪麻黄碱）的含量增加了64.0%;甘草酸含量增加了13.50%;而甘草苷含量降低了19.38%。药效实验证明,甘草与麻黄配伍后抗炎作用较甘草麻黄单煎液明显增强。从而在主要成分的变化程度上揭示了甘草与麻黄配伍过程中的增效机理。     

Analysis of Pesticides in Water Samples Using GC-ECD and GC-MS/MS Techniques

Abstract

A pesticide multiresidue method for determining dichlorvos, naled. lindane, diazinon. chlorpyri-fos-methyl, dichlofluanid, chlorpyrifos, folpet, α– and β-endosulfan, endosulfan-sulphate, fen-propathrin and acrinathrin in water samples at the levels required by the EEC Drinking Waters Directive has been developed. The pesticides were selected among the most used during die last 20 years in Almeria (Spain), where there is a high agricultural activity. Solid Phase Extraction (SPE) was selected as extraction method after being compared with Liquid-Liquid Extraction (LLE). Moreover, different gas chromatographic detectors (Electron Capture Detector, ECD; Mass Spectrometer, MS; Tandem Mass Spectrometer, MS/MS) were compared. The best results of repeatability and sensitivity were obtained for ECD and MS/MS.     

气相色谱-串联质谱法测定稻米中毒死蜱及其代谢物

提出了气相色谱-串联质谱法测定稻米中毒死蜱及其代谢物3,5,6-三氯-2-羟基吡啶(TCP)含量的方法。样品经含体积分数为1%盐酸的乙腈提取,盐析并浓缩至近干后,残渣用乙酸乙酯溶解TCP用N-甲基-N-叔丁基二甲基硅基三氟乙酰胺衍生化,用气相色谱-串联质谱法测定,外标法定量。毒死蜱及TCP的质量浓度与峰面积均在0.02～0.4mg.L-1范围呈线性关系,测定下限(10S/N)依次为0.5,0.2μg.kg-1。在3个浓度水平下进行了回收和精密度试验,毒死蜱和TCP的回收率分别在94.3%～111.9%和95.1%～109.6%范围内,相对标准偏差(n=5)分别在1.7%～4.0%和3.1%～11.6%范围内。     

气相色谱-串联质谱法测定蔬菜和水果中三氯生及甲基三氯生的含量

提出了应用气相色谱-串联质谱法测定蔬菜(西红柿、黄瓜等)和水果(橙子、苹果等)中潜在的污染物三氯生(TCS)和甲基三氯生(MTCS)的含量的方法,以期有助于对此污染物在蔬菜、水果等食品中的污染问题的研究,并应用于农产品质量的安全监测之中。将样品分别去皮后切块,匀浆后于-22℃保存。称取样品5.00g,先后2次用乙酸乙酯(每次10mL)超声提取10min后离心10min,合并2次的提取液。将提取液吹氮蒸发至近干。加入衍生试剂体积比为99∶1的N,O-双(三甲基硅烷基)三氟乙酰胺-三甲基氯硅烷混合溶液100μL,在60℃下进行衍生化反应40min。反应结束后,将溶液吹氮至近干,用乙酸乙酯1.0mL溶解残渣。所得溶液供气相色谱-串联质谱法分析。用DB-17MS毛细管色谱柱(30m×0.25mm,0.25μm)在150~290℃区间按程序升温条件进行分离,在电子轰击离子源及多反应监测模式下进行质谱测定。经试验确定,用两种扫描程序分别扫描,TCS衍生物的母离子和子离子依次为m/z 362,347和m/z 360,345,MTCS的母离子和子离子则均为m/z 304,254。测得TCS衍生物和MTCS的标准曲线的线性范围均为0.4~20.0μg·L^-1,其检出限(3S/N)为4~6ng·kg^-1。按标准加入法进行回收试验,测得TCS衍生物和MTCS在4种蔬菜、水果中的回收率为91.5%~107%和94.7%~111%。     

GC-MS/MS法测定沉积物和生物样品中邻苯二甲酸酯

采用固相萃取(SPE)和QuEChERS技术结合气相色谱-串联质谱(GC-MS/MS)技术,建立了养殖海域沉积物和生物样品中16种邻苯二甲酸酯(PAEs)定量分析方法.沉积物样品以二氯甲烷为提取溶剂,经PSA-Silica固相萃取柱净化,生物样品以乙腈为提取溶剂,经150.0 mg N-丙基乙二胺(PSA)、150.0...     

GC-MS/MS Quantification of EGFR Inhibitors, β-Sitosterol,Betulinic Acid, (+) Eriodictyol, (+) Epipinoresinol,and Secoisolariciresinol,in Crude Extract and Ethyl Acetate Fraction of Thonningia sanguinea

Medicinal plants are widely used in folk medicine to treat various diseases. Thonningia sanguinea Vahl is widespread in African traditional medicine, and exhibits antioxidant, antibacterial, antiviral, and anticancer activities. T. sanguinea is a source of phytomedicinal agents that have previously been isolated and structurally elucidated. Herein, gas chromatography combined with tandem mass spectrometry (GC-MS/MS) was used to quantify epipinoresinol, β-sitosterol, eriodictyol, betulinic acid, and secoisolariciresinol contents in the methanolic crude extract and its ethyl acetate fraction for the first time. The ethyl acetate fraction was rich in epipinoresinol, eriodictyol, and secoisolariciresinol at concentrations of 2.3, 3.9, and 2.4 mg/g of dry extract, respectively. The binding interactions of these compounds with the epidermal growth factor receptor (EGFR) were computed using a molecular docking study. The results revealed that the highest binding affinities for the EGFR signaling pathway were attributed to eriodictyol and secoisolariciresinol, with good binding energies of −19.93 and −16.63 Kcal/mol, respectively. These compounds formed good interactions with the key amino acid Met 769 as the co-crystallized ligand. So, the ethyl acetate fraction of T. sanguinea is a promising adjuvant therapy in cancer treatments.     

Multi-residue analysis and ultra-trace quantification of 36 priority substances from the European Water Framework Directive by GC-MS and LC-FLD-MS/MS in surface waters

A multi residue analysis was developed for screening, quantification and confirmation of 36 priority organic compounds included in the 2000/60/EC European Water Framework Directive. The compounds analyzed included 19 pesticides, 8 PAH, 5 endocrine-disruptors and 4 organochlorine compounds. The method was developed in three steps. First, automated off-line solid-phase extraction using Strata X cartridges was optimized to trap simultaneously the 36 studied compounds. Second, the more volatile compounds were analysed by gas chromatography coupled to mass spectrometry with electron impact ionisation in selected ion monitoring mode (SIM). Third, the last 20 compounds were detected and quantified, in one run, by liquid chromatography coupled to fluorescence detector and tandem mass spectrometry. The excellent selectivity and sensitivity allowed us satisfactory quantification and confirmation at levels as low as 0.2-67 ng L⁻¹ with recoveries between 59 and 105%. Such methodology was then applied to French surface waters: all the waters present organic contaminants, and their concentration varied according to the origin and nature of substances.     

GC-MS/MS multi-residue method for the determination of organochlorine pesticides,polychlorinated biphenyls and polybrominated diphenyl ethers in human breast tissues

In this work, a multiresidue method for the quantification and confirmation of around 30 organohalogenated compounds in human breast tissue samples has been developed. Analytes tested included organochlorine (OC) (pesticides and polychlorinated biphenyls) and organobromine (OBr) (polybrominated diphenyl ether) compounds. The approach is based on a simple extraction with hexane, followed by a SPE clean-up using silica cartridges and final measurement by GC coupled to triple quadrupole MS. Analyses were performed in both ionizations, electron impact (EI) (selected reaction monitoring (SRM) mode) and negative chemical ionization (NCI) (selected ion recording (SIR) mode). Three isotopically labeled standards were added before extraction and used as surrogates: HCB-¹³C₆, lindane-D₆ and p,p′-DDE-D₈. The method was validated in terms of accuracy, precision, LOQ and LOD and confirmation reliability, using breast tissue spiked at three concentration levels in the range 1–100 ng/g for OC compounds and at two levels 0.1 and 10 ng/g for OBr compounds (0.5 and 50 ng/g for BDE 209). The usefulness of the developed method was tested by the analysis of real human samples, giving as a result the detection of several OC and OBr compounds in different samples analyzed. The acquisition of at least two SRM transitions (in EI) or ions (in NCI) per analyte allowed positive findings to be confirmed by accomplishment of ion ratios between the quantification and the confirmation transitions or ions.     

气相色谱-串联质谱法测定2-氰基溴苄中3-氰基溴苄和4-氰基溴苄的含量

建立了气相色谱-串联质谱法测定苯甲酸阿格列汀关键起始物料2-氰基溴苄中基因毒性杂质3-氰基溴苄和4-氰基溴苄含量的分析方法。采用50%苯基-50%二甲基聚硅氧烷为固定液的VF-17MS毛细管柱(30m×0.25mm,0.25μm)进行程序升温;进样口温度260℃;以多反应监测(MRM)模式检测。2种待测物均具有较好的线性关系,相关系数均大于0.998 0;检出限(3S/N)均为2.0μg·L^-1;3-氰基溴苄的回收率为92.1%~97.0%;4-氰基溴苄的回收率为102%~109%;供试品溶液、杂质对照品溶液和系统适用性溶液在室温(25℃)下放置18h内稳定。三批生产规模样品中均未检出3-氰基溴苄和4-氰基溴苄。建立的分析方法灵敏度高、分离度好、结果准确,可有效分离并测定2-氰基溴苄中的3-氰基溴苄和4-氰基溴苄含量,为苯甲酸阿格列汀的安全性提供了保障。     

加速溶剂萃取-气相色谱-串联质谱法测定烟丝中5种羧酸苯乙酯的含量及对烟丝加香的均匀性评价

将烟丝样品置于温度(20±1)℃及相对湿度(60±3)%条件下平衡24h。称取此样品4.0g置于Dionex ASE 350萃取仪的34 mL萃取池中,用正己烷作为溶剂进行加速溶剂萃取(ASE)。加速萃取的温度为100℃,静态萃取时间为5min,循环次数为2次。于萃取液中加入乙酸苯甲酯内标(100mg·L^-1)溶液0.50mL,混匀后经0.45μm滤膜过滤,取滤液进行气相色谱-串联质谱法分析。采用HP-5MS毛细管色谱柱(30m×0.25mm,0.25μm),在60~280℃温度区间程序升温模式分离后,按电子轰击离子源和多反应监测模式条件进行串联质谱测定。所测定的5种羧酸苯乙酯的质量浓度均在0.10~10.00mg·L^-1内与其对应的峰面积之间呈线性关系,其检出限(3S/N)均为0.01mg·L^-1。按标准加入法测定了方法的回收率,结果为91.0%~107%,测定值的相对标准偏差(n=6)均小于10%。同一批次内和不同批次间外加标记物的变异系数(CVi)分别为5.8%~8.8%和6.3%~8.4%,说明加香工序的均匀性良好。     

Microwave-assisted extraction and ultrasonic extraction to determine polycyclic aromatic hydrocarbons in needles and bark of Pinus pinaster Ait. and Pinus pinea L. by GC-MS

Two different extraction strategies (microwave-assisted extraction (MAE) and ultrasonic extraction (USE)) were tested in the extraction of the 16 US Environmental Protection Agency (EPA) polycyclic aromatic hydrocarbons (PAHs) from pine trees. Extraction of needles and bark from two pine species common in the Iberian Peninsula (Pinus pinaster Ait. and Pinus pinea L.) was optimized using two amounts of sample (1 g and 5 g) and two PAHs spiking levels (20 ng/g and 100 ng/g). In all cases, the clean-up procedure following extraction consisted in solid-phase extraction (SPE) with alumina cartridges. Quantification was done by gas chromatography (GC) with mass spectrometry (MS), using five deuterated PAH surrogate standards as internal standards. Limits of detection were globally below 0.2 ng/g. The method was robust for the matrices studied regardless of the extraction procedures. Recovery values between 70 and 130% were reached in most cases, except for high molecular weight PAHs (indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene and benzo[ghi]perylene). A field study with naturally contaminated samples from eight sites (four in Portugal and four in Catalonia, Spain) showed that needles are more suitable biomonitors for PAHs, yielding concentrations from 2 to 17 times higher than those found in bark. The levels varied according to the sampling site, with the sum of the individual PAH concentrations between 213 and 1773 ng/g (dry weight). Phenanthrene was the most abundant PAH, followed by fluoranthene, naphthalene and pyrene.     

GC-MS with ethyl chloroformate derivatization for comprehensive analysis of metabolites in serum and its application to human uremia

An optimized method based on GC-MS with ethyl chloroformate derivatization has been developed for the comprehensive analysis of endogenous metabolites in serum. Twenty-two reference standards and serum samples were used to validate the proposed method. The correlation coefficient was higher than 0.9900 for each of the standards, and the LOD varied from 125 to 300 pg on-column. The analytical equipment exhibited good repeatability (RSD<10%) for all of the standards. Both the repeatability and the within-48-h stability of the analytical method were satisfactory (RSD<10%) for the 18 metabolites identified in the serum samples. Mean recovery was acceptable for the 18 metabolites, ranging from 70% to 120% with RSDs of less than 10%. Using the optimized protocol and a subsequent multivariate statistical technique, complete differentiation was achieved between the metabolic profile of uremic patients and that of age- and sex-matched normal subjects. Significantly decreased levels of valine, leucine, and isoleucine and increased levels of myristic acid and linoleic acid were observed in the patient group. This work demonstrated that this method is suitable for serum-based metabolic profiling studies.     

GC-MS/MS法对焙烤食品及其塑料包装材料中25种磷酸三酯类与邻苯二甲酸酯类化合物的同时测定

建立了气相色谱-质谱/质谱(GC-MS/MS)测定焙烤食品及其塑料包装材料中25种磷酸三酯类及邻苯二甲酸酯类化合物的高通量检测方法。焙烤食品以乙腈-丙酮(8∶2,体积比)超声提取,采用50 mg C18和50 mg PSA混合填料进行Qu ECh ERS净化;塑料包装材料经二氯甲烷-甲醇超声提取后直接检测。样液经DB-5 ms色谱柱分离,选择反应监测(SRM)模式测定。25种化合物在各自线性范围内的相关系数不小于0.997 5,方法检出限为10~500μg/kg,平均回收率为80.2%~119.6%,相对标准偏差(n=6)为1.5%~9.4%。该方法操作简单,净化效果好,可有效消除基质效应,适用于不同焙烤食品及其塑料包装材料中磷酸三酯类及邻苯二甲酸酯类化合物的同时测定。     

GC-MS analysis of the bioactive phytoconstituents of various organic crude extracts from the seed kernels of Manilkara bidentata (balata) collected in Trinidad,W.I.

The present study reports the first phytochemical investigation of the seed kernels of Manilkara bidentata (Balata) harvested in Trinidad, W.I. Gas chromatography–mass spectrometry (GC-MS) analysis of the n-hexane, chloroform, ethyl acetate, ethanol and methanol extracts showed a total of 39 components. 2,6,10,14,18-pentamethyl-2,6,10,14,18-eicosapentaene (74.93%), 9-octadecenoic acid, (Z)- 2,3-dihydroxypropyl ester (79.98%), (Z)-ethyl oleate (92.75%), Z,E-2-methyl-3,13-octadecadien-1-ol (80.51%) and 5-(hydroxymethyl)-2-furancarboxyaldehyde (50.32%) were the major constituents identified in the n-hexane, chloroform, ethyl acetate, ethanol and methanol extracts, respectively. The extracts showed the presence of several bioactive components and provides reference data for further research of its active constituents.     

顶空固相微萃取/气相色谱-三重四极杆串联质谱法测定地表水与饮用水中的挥发性有机物

采用部分因子试验设计筛选出顶空固相微萃取的主要影响参数,利用中心复合设计对主要影响参数的取值进行了优化,建立了顶空固相微萃取(HS-SPME)结合气相色谱-三重四极杆串联质谱(GC-MS/MS)测定地表水和饮用水中55种挥发性有机物(VOCs)的分析方法。取5.0 mL样品于顶空瓶中,加入0.75 g NaCl,使用CAR/PDMS 75μm纤维头,萃取温度40℃,萃取时间40 min,解析温度300℃,在GC-MS/MS选择反应监测(SRM)模式下检测,内标法定量。结果表明,55种VOCs在0.04～0.40、0.4～4.0、4.0～100μg/L质量浓度范围内线性良好,相关系数(r~2)均大于0.99,方法的检出限为0.03～80 ng/L,定量下限为0.1～300 ng/L。55种VOCs在0.2、2.0、40μg/L 3个加标水平下的平均回收率为77.3%～124%,相对标准偏差(RSD,n=6)为1.3%～17%。对3种地表水和3种饮用水进行测定,地表水中有37种VOCs被检出,饮用水中有25种VOCs被检出。实验证明,建立的HS-SPME和GC-MS/MS相结合的检测方法具有准确可靠、简单快速、灵敏度高等优点,适用于地表水和饮用水中VOCs的同时测定。