液相色谱串联质谱法测定再造烟叶中的甲基异噻唑啉酮及其氯代物

建立了液相色谱串联质谱测定再造烟叶中的甲基异噻唑啉酮及其氯代物的方法。样品用甲醇做萃取剂,经涡旋振荡,C8 液相色谱柱分离,串联质谱仪MRM 模式检测。结果发现,在0.05~l0mg/L 范围内线性良好,定量限分别为2.5 μg/L、2.8 μg/L,回收率分别为95.2%、92.3%,相对标准偏差<5%。该方法操作简单、效率高、适合推广运用。      

液相色谱-电喷雾串联质谱法测定豇豆中的水胺硫磷

建立了豇豆中水胺硫磷的液相色谱-电喷雾串联质谱分析方法。样品经乙腈超声提取后进行液相色-电喷雾串联质谱分析。方法检出限为0.1μg/kg(S/N=3)。空白样本添加水平在0.1、1.0、5.0μg/kg时,平均回收率为80.1~87.9%,相对偏差(n=6)为6.7~8.1%。使用MRM-IDA-EPI的模式,一次进样可得到MRM色谱图及MS2质谱图。该方法具有前处理简单、回收率高、精密度好,选择性强,灵敏度高的优点,符合农药残留的分析要求。     

高效液相色谱-串联质谱联用技术快速分析水果和蔬菜中毒死蜱及其降解产物

目的 建立高效液相色谱-串联质谱联用技术快速分析蔬菜和水果中毒死蜱及其降解产物的检测方法。方法 从色谱和质谱条件两方面对仪器采集参数优化;以韭菜、芹菜、甘蓝、苹果和柑橘为基质,采用QuEChERS方法进行前处理,考察乙二胺-N-丙基硅烷化硅胶和石墨化炭黑(GCB)对毒死蜱及降解产物的影响;最后根据检出限、定量限、线性范围、基质效应、准确度、精密度等对该方法进行考察。结果 流动相为乙腈和0.1%(V/V)甲酸水,质谱采集模式为ESI⁺,前处理过程中加入GCB 45 mg/5 mL,此时4种目标物在线性范围内线性良好(R2≥0.99),定量限为1～30μg/kg;在3个加标水平下,回收率为66.1%～113.6%,相对标准偏差为1.3%～16.9%。结论 建立的毒死蜱及降解产物残留量的检测方法快速、高效、准确度和重复性好,适用于蔬菜和水果中毒死蜱及其降解产物的测定。     

LC-MS/MS法测定吸烟者和被动吸烟者尿液中的烟碱及其代谢物

以烟碱-d3、可替宁-d3、反3'-羟基可替宁-d3作内标,XDB C18柱作色谱柱,10 mmol/L(pH6.8)乙酸铵水溶液和无水甲醇为流动相,梯度洗脱,流速1 mL/min,采用LC-MS/MS法同时测定了10名吸烟者和5名被动吸烟者尿液中烟碱及其糖苷、可替宁及其糖苷、反3'-羟基可替宁及其糖苷、降烟碱、降可替宁、可替宁氮氧化物和烟碱氮氧化物.结果表明:①烟碱及其代谢物的精密度在2.1%～17.0%之间,回收率在78%～116%之间;②日抽吸20支相同品牌卷烟的吸烟者尿液中烟碱及其9种代谢物的含量差异较大;③被动吸烟者尿液中都检测出烟碱、可替宁、反3'-羟基可替宁,部分检出可替宁糖苷、降烟碱、烟碱氮氧化物,且前3种物质的浓度略高于后3种,但都远远低于吸烟者.烟碱、可替宁、反3'-羟基可替宁有可能作为人体尿液中被动吸烟的生物标记物.     

Determination of aflatoxins in food using LC/MS/MS

 A liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometric method is described for the determination of aflatoxins B₁, B₂, G₁ and G₂ in food with the use of aflatoxin M₁ as an internal standard. The method works well with matrices such as those of figs and peanuts, but there are problems with spices, due to limitations of the clean-up method used. Received: 15 October 1997     

农产品中百速隆残留量的液相色谱-质谱法测定

建立了农产品中除草剂百速隆残留量的液相色谱-质谱(GC/MS)检测方法;样品经溶剂提取、固相萃取柱净化,采用液质联用仪在选择离子监测模式下进行快速定性定量分析,外标法定量,方法检出限为0.01 mg/kg。在大米、苹果、洋葱、猪肝中4种样品中添加不同浓度的百速隆时,其平均添加回收率在78.9%~95.9%之间,相对标准偏差(n=10)为2.1%~8.4%。     

Determination and confirmation of five phenolic antioxidants in foods by LC/MS and GC/MS

Identification and determination of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), nordihydroguaiaretic acid (NDGA), propyl gallate (PG) and tert-butylhydroquinone (TBHQ) by means of LC/MS and GC/MS were examined. These five phenolic antioxidants were detected as their pseudo-molecular ions [M-H]- by LC/MS using a Shim-pack FC-ODS column with drying gas. Moreover, BHA, BHT and TBHQ were detected based on their mass fragment ions by GC/MS. Decomposition of TBHQ, NDGA and PG during analysis could be prevented by the addition of L-ascorbic acid (AsA) to the extraction solvent. All five antioxidants were extracted from nikuman, olive oils, peanut butter, pasta sauce and chewing gum with a mixture of acetonitrile-2-propanol-ethanol (2:1:1) containing 0.1% AsA (AsA mixture), which had been cooled in a freezer and filtered. One part filtrate and 5 parts water were mixed and placed on a Mega-Bond Elut C18 cartridge, except in the case of chewing gum. Lipids in foods were removed on a C18 cartridge by washing with 5 mL of 5% acetic acid, and antioxidants were eluted with 5 mL of AsA mixture. The antioxidants spiked into nikuman, olive oil, peanut butter, pasta sauce and chewing gum were successfully identified and their concentrations determined by LC/MS, and GC/MS with good recoveries.     

高效液相色谱 串联质谱法测定纺织品中苯并三唑类紫外线吸收剂

通过萃取和优化仪器条件,建立了高效液相色谱 串联质谱法（HPLC MS/MS）测定纺织品中2 (2′ 羟基 5′ 甲基苯基) 苯并三唑的含量,并分析了该物质的质谱图和母离子可能的裂解机理。方法采用Varian Pursuit XRs C18色谱柱,含0.1%甲酸的CH3CN H2O溶液(65〖KG-*5〗∶〖KG-*5〗35)作为流动相,并以多反应监测模式进行定性定量分析。结果表明,在0.01~50.00 mg/L范围内,UV P峰面积S与浓度C呈良好的线性关系,回归方程为S=1.0×107C+2.0×106,相关系数为0.999 8,以3σ计算得UV P的检出限为3 ng/L,平均回收率为96.4%~102.6%。该方法灵敏度高、操作简便,可用于纺织品中苯并三唑类紫外线吸收剂中UV P的日常检测。     

塑料包装材料中邻苯二甲酸酯的LC/MS/MS测定方法研究

建立了LC/MS/MS测定塑料包装材料中邻苯二甲酸酯含量的分析方法.将塑料包装材料粉碎后索氏提取,经LC/MS/MS分析在50μg/L～400μg/L范围内呈现良好的线性关系(R2＞0.9985),方法检测限小于35μg,/kg;在50μg/kg、200μ g/kg、400μg/kg三个样品加标水平,PAEs的回收率在91.42％～99.90％之间;方法精密度实验的相对准偏差在5％之内.结果表明该方法准确可靠,精密度较高.     

Determination of spiramycin and tilmicosin in meat and fish by LC/MS

A simple and reliable method using liquid chromatography-electrospray ionization-mass spectrometry (LC/ESI-MS) has been developed for the determination of the macrolide antibiotics spiramycin and tilmicosin in meat and fish. The drugs were extracted from meat and fish with 0.2% metaphosphoric acid-methanol (6:4), and the extracts were cleaned up on an Oasis HLB cartridge (60 mg). Positive ionization produced the molecular related ions, (M + 2H)2+, at m/z 350.2, 422.3 and 435.3 for neospiramycin I, spiramycin I and tilmicosin, respectively. The LC separation was performed on a Capcell Pak MG-C18 column (150 x 2 mm i.d.) with a gradient system of 0.02% formic acid-acetonitrile as the mobile phase at a flow rate of 0.2 mL/min. The molecular-related ions of the drugs were very clear under this condition. The calibration graph for each drug was rectilinear from 0.05 to 5 ng with selected ion monitoring (SIM). The recoveries of the drugs from meat and fish fortified at the level of 0.2 microgram/g was 73.2-89.2%, with high precision. The limits of detection of the drugs in meat and fish were 0.01 microgram/g.     

Determination of para-synephrine and meta-synephrine positional isomers in bitter orange-containing dietary supplements by LC/UV and LC/MS/MS

Dietary supplements that contain bitter orange (Citrus aurantium) fruit as an integrated component have rapidly replaced ephedra-containing dietary supplements for use as weight loss products. However, the safety of bitter orange-containing supplements has been questioned because synephrine, an adrenergic alkaloid and a key component of bitter orange fruit, has potential adverse health effects. Conflicting reports have stated that synephrine exists as the para (p) and/or meta (m) positional isomers in some bitter orange-containing supplements and this is problematic because the p- and m-isomers have distinctly different pharmacological and metabolic activities. Two liquid chromatographic (LC) methods have been developed for the baseline separation and quantitation of p- and m-synephrine in bitter orange-containing supplements. An isocratic LC method that utilizes ultraviolet (UV) absorbance detection and a gradient LC method that utilizes tandem mass spectrometry (MS/MS) detection were optimized for separation of the isomers within a run time of 25 min. Terbutaline was utilized as an internal standard compound in both LC methods. The LC/UV and LC/MS/MS methods demonstrated limits of quantitation (LOQs) for synephrine of ≈30 ng (on-column) and ≈0.02 ng (on-column), respectively, and each method exhibited analytical linearity over three orders of magnitude. Both LC methods were used to evaluate the synephrine levels in a limited selection of commercially available bitter orange-containing supplements. Significantly, m-synephrine was not detected in any of the tested dietary supplements.     

Determination of carbofuran by GLC/NPD and HPLC in tomato fruits

Summary Two analytical methods, using GLC/NPD and HPLC to analyse carbofuran residues in tomatoes, are described. Both methods have shown a high recovery rate, up to 90%, and their detection limits are below the maximum residue limit set by Codex Alimentarius Mundi for carbofuran in tomatoes. Therefore, both methods may be of use in routine analysis of this pesticide in those fruits.

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Rückstandsanalyse von Carbofuran in Tomaten mit GLC/NPD und HPLC

Zusammenfassung Beschrieben werden zwei Arbeitsweisen zur Analyse von Rückständen des Methylcarbamat-Insecticids Carbofuran, die sich gut für routinemäßige Untersuchungen von Tomaten eignen. Die Wiederfin-dungsrate liegt über 90% und die Nachweisgrenze deutlich unter der Höchstmenge des Codex Alimentarius von 0,1 mg/kg.

     

Determination of carbofuran by GLC/NPD and HPLC in tomato fruits

Two analytical methods, using GLC/NPD and HPLC to analyse carbofuran residues in tomatoes, are described. Both methods have shown a high recovery rate, up to 90%, and their detection limits are below the maximum residue limit set by Codex Alimentarius Mundi for carbofuran in tomatoes. Therefore, both methods may be of use in routine analysis of this pesticide in those fruits.     

Determination of flavonoids by LC/MS and anti-inflammatory activity in Moringa oleifera

Moringa oleifera is an important multipurpose tropical tree under-recognized for its nutritional and medicinal properties. Leaves of moringa collected from sub-Sahara Africa were analyzed for phenolic components by HPLC–UV–MS. Twelve flavonoids were identified, including quercetin and kaempferol glucosides and glucoside malonates as major constituents. To facilitate quantitative analysis, acid hydrolysis during extraction of moringa samples was employed to convert the conjugates into their respective flavonoid aglycones, allowing accurate quantitation of total flavonoids as aglycones. Validation of the method demonstrated recoveries ranging from 92.6% to 107.5% for the two analytes. Using this method, total flavonoids from moringa collected from Ghana, Senegal and Zambia were determined and their content ranged from 0.18% to 1.64% (g/dry weight) across the respective environment or country of production and by variety. Moringa was found to exhibit anti-inflammatory activity of constituents-rich varieties. As flavonoid malonates are among the major constituents in the original plant material, a study examining thermal stability of flavonoid malonyl derivatives showed that these compounds were not thermally stable and easily cleaved to yield their respective flavonoid glycosides.     

Determination of ochratoxin A in beer by LC–MS/MS ion trap detection

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus ochraceus and Penicillium verrucosum. It was analysed in food and beverages so far. Due to its toxicity, the European community issued directives and some countries own regulations for OTA contents in food, feed, and beverages. This work describes a method for the determination of OTA in beer. It is based on a combined anion exchange/reversed phase clean-up and liquid chromatography with tandem mass spectrometry. This method was compared with a modified standard method and validated on the basis of spiked beer samples. The accuracy was checked with statistical tools (t-test). Due to its good reproducibility, repeatability and robustness this method is a promising alternative to LC–FD (fluorescence detection) techniques.     

Determination of the herbicide isoproturon in cereal grains and pasta by LC with LC/MS confirmation

A method was developed for the determination of the herbicide isoproturon in wheat, maize, oats and pasta, with a limit of determination of 0.05 mg kg^-1. Isoproturon was extracted from moistened samples using a mixture of acetone, hexane and dichloromethane. The resulting extract was cleaned-up by solid-phase extraction using aminopropyl-bonded silica cartridges and analysed by reversed-phase liquid chromatography with photodiode array detection. Confirmation was by electrospray liquid chromatography-mass spectrometry. Recoveries from seven samples of each of the four matrices spiked with isoproturon at 0.05 and 0.5 mg kg^-1 were in the range 88-104%. The method was used to monitor cereal grains and pasta as part of the UK food monitoring programme.     

Determination of seventeen pesticide residues in agricultural products by LC/MS

Residues of 17 pesticides in agricultural products were determined by LC/MS with an atmospheric pressure chemical ionization (APCI) interface in both positive and negative ion modes. Pesticides were extracted with acetonitrile, and the extracts were cleaned-up with a primary and secondary amine (PSA) mini-column eluted with acetone-hexane (1:1). Rice, orange and potato were spiked with the 17 pesticides at 0.1 microgram/g and analyzed by the proposed method. The average recoveries of these pesticides usually ranged from 70 to 98% and the relative standard deviations were usually around 10%. These results suggested that LC/MS with APCI could be used to determine the residue levels of the 17 pesticides in these crops.     

HPLC/MS测定白酒中的微量甜味剂

建立了测定白酒中微量甜蜜素、糖精钠、安赛蜜的HPLC/MS分析方法。样品用水适当稀释,直接进样测定。采用C18柱分高,在ESI负离子模式下检测。甜蜜素、糖精钠、安赛蜜测定的检出限分别为0.01、0.05和0.05mg/L,加标回收率分别为96.8%、96.0%和95.8%。     

超高效液相色谱-串联质谱法测定果蔬中4种乙撑二硫代氨基甲酸酯农药残留

目的 建立超高效液相色谱-串联质谱法(UPLC-MS/MS)测定蔬菜、水果中4种乙撑二硫代氨基甲酸酯类农药残留量的方法。方法 试样采用L-半胱氨酸盐酸盐和碱性EDTA-Na₂溶液进行提取,碘甲烷衍生,QuEChERS原理净化浓缩,UPLC-MS/MS对乙撑二硫代氨基甲酸酯类农药衍生物进行测定,外标法定量。结果 水果的检出限为5μg/kg,蔬菜的检出限为10μg/kg,相关系数大于0.998,添加回收率的范围为82.3%～115.1%,相对标准偏差为2.3%～6.9%。结论 本文所建立的方法能够满足多种水果和蔬菜中乙撑二硫代氨基甲酸酯类农药快速准确检测。     

HPLC-MS测定白酒中氨基甲酸酯类农药残留

建立了一种同时对白酒中10种氨基甲酸酯类农药残留的HPLC-MS测定方法。色谱条件:色谱柱Phenomenex-LunaCN100A(250mm×4.6mm×5μm),流动相乙腈-水(在40min内乙腈由20%变为80%),流速1.00mL/min,检测波长195nm,柱温25℃,进样量20μL。质谱条件:电喷雾离子源(ESI+源),扫描范围(m/z)为50～350,干燥气温度350℃,干燥气流速8.0mL/min,雾化气压力275.86kPa。样品制备:白酒样品用固相萃取处理后,氮吹浓缩,乙腈定容至2mL。结果表明,10种氨基甲酸酯类农药残留在0.05～3μg范围积线性关系良好,相关系数R2>0.99。平均回收率在72.6%和97.6%,RSD在2.6%～5.9%之间。结论:方法灵敏度高、操作简便、结果准确,可用于酒样中痕量农药残留的含量测定。