气相色谱-串联质谱法快速筛查测定中药材中144种农药残留

利用气相色谱-串联质谱(GC-MS/MS)检测技术,采用QuEChERS法作为样品前处理方法,建立了能应用于11种中药材中144种农药残留的检测方法。探究了样品前处理过程中提取溶剂、缓冲盐体系、净化剂组成和用量对样品提取、净化等方面的影响,最终确定了用乙腈提取,甲苯复溶,以混合净化剂净化,过有机膜后经GC-MS/MS测定,外标法定量。144种农药在10~2000 μg/kg之间线性关系良好,相关系数(r²)>0.983;除乙酰甲胺磷、灭虫威、西玛津、克菌丹、异狄氏剂、异菌脲外,其余农药的定量限(LOQ)均低于20 μg/kg;在20、50、200 μg/kg的添加水平下,除乙酰甲胺磷、艾氏剂和双甲脒回收率偏低外,其余141种农药的平均回收率在74.3%~111.8%之间,相对标准偏差(RSD)为0.5%~14.6%。与已有的标准方法对比,此方法不仅检测结果一致,而且高效、快速,准确性好,灵敏度高,适用于中药材中144种农药残留的快速筛查与定量分析。     

Determination of cyclic and linear siloxanes in soil samples by ultrasonic-assisted extraction and gas chromatography-mass spectrometry

A rapid method, based on sonication-assisted extraction in small columns (SAESC) and subsequent quantification and identification by gas chromatography-mass spectrometry (GC-MS), was developed for the determination of cyclic and linear siloxanes in soil. In the experiments with spiked samples (10-50 ng g(-1)), the recovery of cyclic and linear siloxanes ranged from 87.7 to 108.0% and from 84.9 to 107.6%, respectively. The validated method was used to determine the levels of these compounds in various types of soil samples collected from different locations in Spain. The cyclic siloxanes, decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) were detected in all the soil samples analyzed at concentrations from 9.2 to 56.9 ng g(-1) for D5 and from 5.8 to 27.1 ng g(-1) for D6 in agricultural soils and from 22 to 184 ng g(-1) for D5 and from 28 to 483 ng g(-1) for D6 in industrial soils. The total linear siloxanes concentrations (L5-L14) (sum of the 10 congeners) ranged from 191 to 292 ng g(-1) in agricultural soils and from 1411 to 8532 ng g(-1) in industrial soils.     

气相色谱-串联质谱法测定茶叶中88种农药残留量

采用气相色谱-串联质谱(GC-MS/MS)分析技术,建立了高灵敏度检测茶叶中88种农药残留量的方法。目标化合物经加速溶剂萃取(ASE), Carb/NH2净化小柱净化,乙腈-甲苯(3:1, v/v)洗脱,采用GC-MS/MS测定。对方法的准确性、精密度、线性范围、最低检出限(LOD)和定量限(LOQ)进行了测试。其中87.5%的农药在低水平(6.4 μg/kg)的加标回收率为70%～100%; 87.5%的农药的相对标准偏差(RSD)小于15%。每个化合物均采用灵敏度最高的离子对进行定量,并采用空白茶叶基质配制标准工作液。LOQ以10倍信噪比(S/N=10)计算,86.4%农药的LOQ值低于10 μg/kg。该方法灵敏度高、准确、可靠,适用于绿茶、乌龙茶、红茶以及普洱茶中多种农药残留量的检测。     

分析保护剂补偿基质效应-气相色谱-质谱法快速测定水果中40种农药残留

建立了水果中40种农药化合物的气相色谱-质谱(GC-MS)多残留检测方法,评价了添加分析保护剂对农药残留分析的补偿基质效应和对定量结果可靠性的影响。采用可以溶于丙酮有机溶剂的聚乙二醇Polyethylene Glycol 400(PEG 400)和橄榄油作为保护剂组合进行定量分析。水果样品采用乙腈提取,微型固相萃取小柱净化,大体积进样,GC-MS选择离子监测(SIM)模式检测。40种农药化合物在1～200 μg/L范围内线性关系良好,线性相关系数在0.99以上,检出限(以信噪比为3计)为0.1～3.0 μg/L。除乐果外,其他化合物的添加回收率为75%～119%,相对标准偏差均小于16.6%。通过对添加分析保护剂的校准曲线与基质匹配校准曲线的定量准确性的比较,发现加入分析保护剂方法可以代替基质匹配校正方法,同时采用大体积进样和微型固相萃取净化相结合的方法,大大减少了样品前处理量。将所建立的分析保护剂方法用于苹果、桃子、橙子、香蕉和葡萄等水果样品的分析,基质补偿效应良好,有效地克服了水溶性分析保护剂对气相色谱分析有影响的缺点。     

气相色谱-串联质谱技术分析烟草中的132种农药残留

利用气相色谱-串联质谱(GC-MS/MS)检测技术,建立了检测烟草中的132种农药残留的高灵敏度方法。分析过程中考察了不同萃取溶剂、不同缓冲盐体系、不同净化剂对目标物回收率的影响。最终确定烟草样品以乙腈进行提取,以N-丙基乙二胺(PSA)与碳18(C18E)的混合净化剂进行净化,氮气吹近干后用正己烷-丙酮(9:1, v/v)复溶,过有机滤膜后进行GC-MS/MS测定,内标法定量。132种农药在20～2000 μg/kg之间线性关系良好(r2 ＞0.99);所有农药的方法定量限(LOQ, S/N=10)均低于20 μg/kg;在50、200、500 μg/kg的加标水平下,除灭蚁灵及六氯苯回收率稍低外,其他农药的平均回收率为68.10%～123.15%,相对标准偏差(RSD)为1.79%～19.88%。对国际烟草科学研究合作中心(CORESTA)2012年共同实验的烟草样品进行检测,对比本方法与已有的标准方法,其结果一致性较好。该方法准确、可靠,灵敏度好,适用于烟草中132种农药残留的快速筛查与定性、定量分析。     

Quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria by gas chromatography-mass spectrometry

Simple and rapid quantitative determination of fatty-acid-based biofuels is greatly important for the study of genetic engineering progress for biofuels production by microalgae. Ideal biofuels produced from biological systems should be chemically similar to petroleum, like fatty-acid-based molecules including free fatty acids, fatty acid methyl esters, fatty acid ethyl esters, fatty alcohols and fatty alkanes. This study founded a gas chromatography-mass spectrometry (GC-MS) method for simultaneous quantification of seven free fatty acids, nine fatty acid methyl esters, five fatty acid ethyl esters, five fatty alcohols and three fatty alkanes produced by wild-type Synechocystis PCC 6803 and its genetically engineered strain. Data obtained from GC-MS analyses were quantified using internal standard peak area comparisons. The linearity, limit of detection (LOD) and precision (RSD) of the method were evaluated. The results demonstrated that fatty-acid-based biofuels can be directly determined by GC-MS without derivation. Therefore, rapid and reliable quantitative analysis of fatty-acid-based biofuels produced by wild-type and genetically engineered cyanobacteria can be achieved using the GC-MS method founded in this work.     

Analysis of salicylate and benzophenone-type UV filters in soils and sediments by simultaneous extraction cleanup and gas chromatography-mass spectrometry

An analytical method for the determination of UV filters in soil and sediment has been developed and validated considering benzophenones (BP) and salicylates as target analytes. Soil and sediment samples were extracted with ethyl acetate-methanol (90:10, v/v) assisted with sonication, performing a simultaneous clean-up step. Quantification of these compounds was carried out by gas chromatography-mass spectrometry (GC-MS) after derivatization of the extracts with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Recoveries from spiked soil samples ranged from 89.8% to 104.4% and they were between 88.4% and 105.3% for spiked sediment samples. The effect of the residence time and soil moisture content on the recovery of these compounds was also studied. The precision, expressed as relative standard deviation, was in all cases below 6.1% and the limits of detection (S/N=3) varied from 0.07 to 0.10 ng g(-1) and from 0.11 to 0.28 ng g(-1) for soils and sediments, respectively. The validated method was applied to the analysis of five benzophenone and two salicylate UV filters in soil and sediment samples collected in different areas of Spain.     

气相色谱-串联质谱法快速测定禽蛋中203种农药及化学污染物残留

建立了禽蛋中203种农药及化学污染物残留的气相色谱-串联质谱(GCMS/MS)检测方法.样品用乙腈振荡提取,经ODS C18+Carb串联固相萃取柱净化,乙腈-甲苯(3:1,v/v)洗脱,洗脱液浓缩至0.5mL,氮吹至近干,加1mL正己烷超声溶解后,在气相色谱-串联质谱多反应监测(MRM)模式下进行测定.在1倍MRL(...     

Simultaneous determination of 118 pesticide residues in Chinese teas by gas chromatography-mass spectrometry

An efficient and sensitive method for simultaneous determination of 118 pesticide residues in teas has been established and validated. A multi-residue analysis of pesticides in tea involved extraction with ethyl acetate-hexane, clean-up using gel permeation chromatography (GPC) and solidphase extraction (SPE), and subsequent identification and quantification of the selected pesticides by gas chromatography-mass spectrometry (GC-MS). For most of the target analytes, optimized pretreatment processes led to no significant interference with analysis of sample matrix, and the determination of 118 compounds was achieved in about 60 min. In the linear range of each pesticide, the correlation coefficient was R ² ≥ 0.99. At the low, medium and high three fortification levels of 0.05–2.5 mg kg⁻¹, 118 pesticides average recoveries range from 61 % to 121 % and relative standard deviations (RSD) were in the range of 0.6–9.2 % for all analytes. The limits of detection for the method were 0.00030-0.36 mg kg⁻¹, depending on each pesticide.     

超高效液相色谱-串联质谱法测定中药材中三唑类杀菌剂及三嗪类除草剂的残留量

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定甘草、西洋参、三七、人参、丹参5种中药材中10种三唑类杀菌剂、18种三嗪类除草剂(包括有毒代谢物)残留量的分析方法。采用QuEChERS前处理方法,样品经1%(v/v)醋酸乙腈提取,乙二胺-N-丙基硅烷(PSA)净化处理,以Shim-pack XR-ODSII(75 mm×2.0 mm)为色谱柱,0.05%(v/v)甲酸溶液-乙腈为流动相梯度洗脱,在多反应监测(MRM)模式下测定。25种农药及其3种有毒代谢物的定量限(S/N≥10)为0.20～5.52 μg/kg;检出限(S/N≥3)为0.10～2.57 μg/kg;在各自的考察浓度范围内线性关系良好(r≥0.999);在0.20～55.2 μg/kg添加水平内,平均加标回收率为70.6%～125.7%,RSD为0.7%～14.2%。该方法样品前处理简单、快速、灵敏,可用于中药材中三唑类杀菌剂和三嗪类除草剂农药残留量的快速筛查。     

Improved peak selection strategy for automatically determining minute compositional changes in fuels by gas chromatography-mass spectrometry

During the development of automated computational methods to detect minute compositional changes in fuels, it became apparent that peak selection through the spectral deconvolution of gas chromatography-mass spectrometry (GC-MS) data is limited by the complexity and noise levels inherent in the data. Specifically, current techniques are not capable of detecting minute, chemically relevant compositional differences with sufficient sensitivity. Therefore, an alternative peak selection strategy was developed based on spectral interpretation through interval-oriented parallel factor analysis (PARAFAC). It will be shown that this strategy outperforms the deconvolution-based peak selection strategy as well as two control strategies. Successful application of the PARAFAC-based method to detect minute chemical changes produced during microbiological growth in four different inoculated diesel fuels will be discussed.     

气相色谱-串联质谱技术分析烟草中49种农药残留

采用改进的QuEChERS(quick, easy, cheap, effective, rugged and safe)前处理法,结合气相色谱-串联质谱(GC-MS/MS)技术建立了检测烟草中49种农药残留的分析方法。样品用含0.1%乙酸的乙腈溶液提取,提取液被氮吹至干后,残渣用乙腈-乙酸乙酯(1:1, v/v)溶液溶解,溶解液经N-丙基乙二胺(PSA)吸附剂、无水MgSO4、C18吸附剂净化后,直接进行GC-MS/MS测定,内标法定量。实验结果表明,49种农药在低质量浓度(0.05 μg/L)的加标水平下的平均加标回收率为60.4%～104.8%,高质量浓度(5 μg/L)的平均加标回收率为70%～115%,相对标准偏差均小于15%;其中16种农药的方法检出限(LOD)分别为0.01～0.03 μg/kg,其余33种农药的LOD均小于0.01 μg/kg;相关系数都大于或等于0.991。该方法样品前处理简单、分析时间短、灵敏度和精密度均符合农药多残留痕量检测技术的要求,适用于烟草中多种农药残留的检测。     

Evaluation of beer deterioration by gas chromatography-mass spectrometry/multivariate analysis: a rapid tool for assessing beer composition

Beer stability is a major concern for the brewing industry, as beer characteristics may be subject to significant changes during storage. This paper describes a novel non-targeted methodology for monitoring the chemical changes occurring in a lager beer exposed to accelerated aging (induced by thermal treatment: 18 days at 45 °C), using gas chromatography-mass spectrometry in tandem with multivariate analysis (GC-MS/MVA). Optimization of the chromatographic run was performed, achieving a threefold reduction of the chromatographic time. Although losing optimum resolution, rapid GC runs showed similar chromatographic profiles and semi-quantitative ability to characterize volatile compounds. To evaluate the variations on the global volatile signature (chromatographic profile and m/z pattern of fragmentation in each scan) of beer during thermal deterioration, a non-supervised multivariate analysis method, Principal Component Analysis (PCA), was applied to the GC-MS data. This methodology allowed not only the rapid identification of the degree of deterioration affecting beer, but also the identification of specific compounds of relevance to the thermal deterioration process of beer, both well established markers such as 5-hydroxymethylfufural (5-HMF), furfural and diethyl succinate, as well as other compounds, to our knowledge, newly correlated to beer aging.     

应用分析保护剂补偿基质效应与气相色谱-质谱快速检测果蔬中农药多残留

食品中农药残留超标是食品安全管理的一项重要内容。目前,我国普遍采用元素选择检测器进行果蔬样品中农药残留检测工作,前处理过程操作繁杂,然后分别进行各类农药的定性定量,费时费物。国内外农残分析工作者已开始应用气质联用技术[1-7]进行农药测定,有些农药(尤其是极性较强的     

气相色谱-串联质谱法测定水果中50种农药残留

建立了气相色谱-串联质谱测定水果中50种农药残留的分析方法。考察了无缓冲盐体系、乙酸盐缓冲体系和柠檬酸盐缓冲体系提取水果中50种农药的有效性,并对比了乙二胺-N-丙基硅烷（PSA）吸附剂净化和SinChERS-Nano柱净化两种净化方法。结果表明,存在缓冲盐体系的QuEChERS方法提取效果更好且两种缓冲盐体系无明显差别,最后选择乙酸盐缓冲体系;通过比较净化效果和总离子流色谱图,发现SinChERS-Nano柱净化的效果更好。对50种农药进行加标回收试验,发现甲胺磷、乙酰甲胺磷、氧化乐果、三氯杀螨醇、百菌清这5种农药回收率为71.2~129.2%,其他45种农药的回收率为79.1~122.3%。方法的检出限（LOD）为0.3~3.0 μ g/kg;定量限（LOQ）为1.0~10.0 μ g/kg。该方法适用于柑橘、葡萄等水果中50种农药残留的快速筛查分析。     

免疫亲和柱净化-液相色谱-串联质谱法测定中药材中的14种真菌毒素

依次采用磷酸盐缓冲液(PBS)和甲醇-PBS溶液提取样品,以多功能免疫亲和柱净化,采用液相色谱-串联四极杆质谱检测,可同时测定中药材中的黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、伏马毒素B1、伏马毒素B2、T-2毒素、HT-2毒素、赭曲霉毒素A(OTA)、玉米赤霉烯酮等14种真菌毒素。优化条件下,真菌毒素的定量限(LOQ)为1～5 μg/kg, 4种中药材基质(人参、桔梗、板蓝根、麦门冬)中3个不同添加水平的平均回收率(n=6)为71.9%～99.7%,相对标准偏差(RSD)为4.8%～15.8%。该方法的检测速度快,中药材复杂基质的干扰较少,结果准确、可靠,定量限可满足国内外中药材真菌毒素相关限量的要求。     

气相色谱-负化学源质谱法测定蔬菜中17种拟除虫菊酯类农药残留量

建立了气相色谱-负化学源质谱检测蔬菜中17种拟除虫菊酯类农药残留量的方法。样品中的目标物经乙腈提取后,用乙二胺-N-丙基甲硅烷(PSA)和石墨化炭黑填料进行分散固相萃取净化,气相色谱-负化学源质谱选择离子监测模式测定,同位素内标法定量。在甜豌豆、绿花菜和大葱基质中均未见干扰所有农药测定的现象。17种拟除虫菊酯类农药的定量限均为0.02～5 μg/kg。在10、20、30和100 μg/kg等4个添加水平下,所有农药的回收率均为71.0%～139.0%,相对标准偏差≤12.8%。该方法可作为蔬菜中17种菊酯类农残检测的确证方法。     

气相色谱-串联质谱双内标法测定茶叶中53种农药残留

建立了气相色谱-串联质谱（GC-MS/MS）动态多反应离子监测（dMRM）模式,结合串联双色谱柱检测茶叶中53种农药残留量的分析方法。样品中加入QuEChERS缓冲盐,用乙腈提取,采用石墨化炭黑/氨基柱（ENVI-Carb/NH₂）净化。为减少农药在GC-MS/MS分析中基质效应的影响,在标准溶液中加入古洛糖酸内酯和山梨醇作为保护剂,用蒽醌-D8和磷酸三苯酯作双内标定量。结果表明,除了氯氰菊酯的线性范围是40~1000 μg/L外,其他52种农药的线性范围均为20~500 μg/L,线性关系良好,相关系数均大于0.99;有28种农药的定量限（LOQ）小于10 μg/kg,其余25种农药的定量限为10~20 μg/kg;加标回收率为72.5%~130.9%;相对标准偏差（RSD）为0.4%~19.4%。该方法能有效地减少茶叶在GC-MS/MS上的基质效应,操作简单快速,灵敏度和选择性高,适用于农药残留的日常检测。     

气相色谱-质谱法测定蔬菜和水果中193种农药的残留量

在系统优化固相萃取吸附剂填料类型、洗脱溶剂种类及体积的基础上,建立了蔬菜和水果中193种农药残留的气相色谱-质谱(GC-MS)检测方法。样品经乙腈均质提取,C₁₈/PSA固相萃取柱净化,乙腈洗脱,GC-MS选择离子监测(SIM)模式检测,以磷酸三苯酯内标法定量。结果表明,130种农药在10~1000 μg/L、34种农药在20~1000 μg/L、26种农药在50~1000 μg/L、3种农药在100~1000 μg/L范围内线性关系良好,相关系数为0.9967~1.0000,方法检出限(以信噪比为3计)为0.04~8.26 μg/kg,添加回收率为71.6%~117.9%,相对标准偏差为3.0%~11.8%。该方法样品处理简单快速,相比其他多残留分析方法净化效果好,其灵敏度和选择性明显提高,适用于日常检测工作。     

同位素稀释气相色谱-质谱法测定土壤/底泥中23种有机氯农药

建立了同位素稀释气相色谱-质谱法(ID-GC-MS))测定土壤/底泥中23种有机氯农药残留的分析方法。样品经干燥、研磨、筛分处理后用250 mL丙酮-正己烷(体积比为1:1)混合溶剂进行索氏提取24 h,再经铜粉、凝胶渗透色谱和弗罗里硅土固相萃取柱净化,最后用DB-5毛细管柱进行分离和电子轰击电离源质谱在选择离子监测模式下进行检测,并用 13C标记同位素稀释内标法定量。实验结果表明,23种化合物的标准曲线的线性相关性良好,线性范围为50～1600 μg/L,同位素内标的回收率范围为60%～110%,相对标准偏差为1.5%～18%;方法的检出限为0.20～10.3 μg/kg。该方法的净化效果较好,定量准确,适用于土壤/底泥这类复杂基质中农药残留的确证分析。