X射线荧光光谱法结合化学计量学检验橡胶手套的研究

橡胶手套是犯罪现场常能提取的物证。希望建立一种准确可靠且快速简便的光谱分析方法,能够对此类物证进行区分检验。本文使用X-MET7000手持式X荧光光谱能量色散型分析仪,实验条件电压为40kV,电流为60mA,样品量为1cm×1cm,测试时间90s,依次对35个不同品牌的橡胶手套样品进行检验,先通过成分将其分为两大类,然后依据元素含量及含量比进行分组,达到了很好的检验效果。并对实验数据进行系统聚类处理。此方法检验犯罪现场橡胶手套快速准确且无损检材,可快速进行同一认定,确定检材的品牌及来源,为公安机关快速定位嫌疑人提供帮助。     

生物样本中的甲基苯丙胺和氯胺酮含量的检测研究及其体内分布初探

建立了生物样本中甲基苯丙胺和氯胺酮的定量检验方法,该方法应用固相萃取与工作曲线气相色谱法(GC/NPD)对中毒者血、尿、胃内容、肝、脑等检材进行含量测定.通过实际案件,验证了该法具有样品处理简单、提取效率高、分析速度快等优点.案件数据表明,由口服引起的中毒途径,胃内容的含量最高,其次是尿、肝、脑、血等检材,进一步证实了...     

离子色谱法结合红外光谱法检验氯化琥珀胆碱

建立了离子色谱法结合红外光谱法检验案件中氯化琥珀胆碱的分析方法。用离子色谱法使离子分离后,采用电导检测器检测,同时结合红外光谱法将检材样品挥干后与溴化钾压片用红外光谱仪检测。结果表明,该方法能从案件检材中检出氯化琥珀胆碱成分,相似度达到96%。所建立的方法操作简单,检测灵敏,结果准确,可用于刑事案件中检材的快速检验。     

可视化阵列传感器技术鉴别不同香型白酒

决定白酒香型的物质种类繁多,成分复杂.采用可视化阵列传感器技术对中国白酒五大香型的代表酒样进行检测,在可视化区分的基础上采用分层聚类分析、主成分分析等统计分析方法,对检测结果进行分析.不同香型的白酒在聚类分析中可以正确归类,利用主成分分析得到的前3个主成分所代表的白酒75.8%的信息量就可以将不同香型白酒完全区分开,表...     

红外光谱结合X射线荧光光谱检验塑料 打包带(绳)的研究

建立简便快捷的检验塑料打包带(绳)的光谱分析方法。利用傅里叶变换红外光谱仪和X射线荧光光谱仪,对33个不同来源的塑料打包带(绳)样品进行检验分析。结合红外光谱成分填料分析与XRF元素比例分析,达到对塑料打包带(绳)样品准确区分的目的。该方法简便快速,准确可靠且无损检材,可应用于鉴定塑料打包带(绳)物证。     

乌头碱的LC-MS定量分析

乌头生物碱各成分毒性差异很大,其中乌头碱的毒性为其它成分的100-2000倍,是引起中毒和死亡的主要原因。乌头生物碱种类多,在煎煮或泡制过程中易水解产生不同水解产物,进入体内后代谢情况又不明,因此采用液相色谱方法对体内检材乌头碱成分仅靠保留时间确定依据不足,定量工作更是无法开展。但在现实生活中炮制后的乌头植物可入药,且炮制过的乌头植物也可检出少量原碱。遇到体内检材中检验出乌头生物碱成分时,办案单位往往希望有一个量的甄别。经查阅资料,未见体内检材(如血、肝、尿等)中乌头碱含量的报道。我们应用LC-MS,采用646.4单离子扫描方式对实际案例血中乌头碱含量进行了测定,为今后的进一步研究和同行提供数据积累。     

X射线荧光光谱法对橡胶鞋底的分类

为建立案件现场常见橡胶鞋底物证的分类方法,利用X射线荧光光谱,对40个不同品牌、不同系列的橡胶鞋底样品中的无机元素进行了检验。并结合多元统计学,分别选用主成分分析法、k均值聚类法及判别分析法等对实验结果进行分析。结果表明,该方法简便快速、结果准确可靠且无损检材,对样品的分类效果较好。利用该方法可以对橡胶鞋底物证进行分类。     

喷墨打印墨水和墨迹可挥发性成分的GC-MS检验

为研究喷墨打印文件的比对区分和溯源技术,建立了一种墨水可挥发性成分的GC-MS分析方法,分别对90种常见市售喷墨打印墨水、纸张墨迹和假币墨迹中的可挥发性成分进行了分析。研究发现,喷墨打印墨水中含有甘油、二甘醇、三甘醇、吡咯烷酮等极性溶剂;同一型号不同颜色的墨水使用相近的配方;不同厂家墨水的配方存在差异;墨水中的可挥发性成分可在纸张中存在较长时间。据此对4起实际案例中缴获的喷墨打印制作的假币进行了检验,检出若干种溶剂成分,通过溶剂特征对假币进行了比对,相关两起假币案件得到串并。本方法筛选出的部分特征溶剂可用于喷墨打印文件的比对区分,并为相关案件的溯源串并提供技术情报。     

高效液相色谱法测定生物检材中毒鼠强

建立了生物检材样品中微量毒鼠强的高效液相色谱法.生物检材样品经用乙酸乙酯提取,在优化的色谱条件下,以ZORBAX Eclipse XDB-C8>(4.6 mm×150 mm,5μm)为分离柱,乙腈-水(15 85,体积比)为流动相,在220 nm波长下进行检测;方法的线性范围为5～500μg·L-1,相关系数为0.999 9,方法的检出限(S/N=3)为0.5μg·kg-1,生物检材样品(包括血浆、胃内容物、肝、心)加标平均回收率在92.3～98.5%之间.相对标准偏差为2.67%～4.53%.     

气相色谱法测定人体血液中乙醇含量的测量不确定度评定

对气相色谱法测定人体血液中乙醇含量的测量不确定度进行评定。人体血液中乙醇含量测量结果的测量不确定度主要来源于相对定量校正因子、检材量、检材中添加内标物叔丁醇的体积、检材中乙醇峰面积的平均值与添加内标物叔丁醇峰面积的平均值之比、无水乙醇的纯度及密度等参数引起的不确定度。当检材中乙醇的含量为0．915mg／mL时,扩展不确定度为O．030mg/mL(k=2)。     

Rapid Separation of Antioxidants in Food Samples by Coelectroosmotic CE

Rapid separation of a group of eight antioxidants by coelectroosmotic capillary electrophoresis and their preliminary determination in foods (cereal, wine, and beer) is described. The compounds studied were protocatechuic acid, salicylic acid, p-hydroxybenzoic acid, vanillic acid, syringic acid, p-coumaric acid, ferulic acid, and sinapic acid. The best separation was achieved by use of a running buffer consisting of 125 mM boric acid, 49 mM disodium hydrogen phosphate, 0.002% (w/v) hexadimethrine bromide, and 2.5 mM α-cyclodextrin, at pH 7.5; the analysis time was less than 3.5 min. Ligration time and peak area reproducibility, studied on the same day (n=4) and on three different days (n=12), showed the method is reproducible. A study of the antioxidant content of cereal, wine, and beer samples was conducted to evaluate the usefulness of the method. Antioxidants were extracted from cereal samples by sonication with methanol and from wine and beer samples by solid-phase extraction with C₁₈ cartridges. This preliminary study showed that seven of the eight compounds could be detected in wine and cereal samples whereas only five were detected in beer samples.     

Determination of ochratoxin A in wine and beer by immunoaffinity column cleanup and liquid chromatographic analysis with fluorometric detection: collaborative study.

The accuracy, repeatability, and reproducibility characteristics of a liquid chromatographic method for the determination of ochratoxin A (OTA) in white wine, red wine, and beer were established in a collaborative study involving 18 laboratories in 10 countries. Blind duplicates of blank, spiked, and naturally contaminated materials at levels ranging from < or =0.01 to 3.00 ng/mL were analyzed. Wine and beer samples were diluted with a solution containing polyethylene glycol and sodium hydrogen carbonate, and the diluted samples were filtered and cleaned up on an immunoaffinity column. OTA was eluted with methanol and quantified by reversed-phase liquid chromatography with fluorometric detection. Average recoveries from white wine, red wine, and beer ranged from 88.2 to 105.4% (at spiking levels ranging from 0.1 to 2.0 ng/mL), from 84.3 to 93.1% (at spiking levels ranging from 0.2 to 3.0 ng/mL), and from 87.0 to 95.0% (at spiking levels ranging from 0.2 to 1.5 ng/mL), respectively. Relative standard deviations for within-laboratory repeatability (RSDr) ranged from 6.6 to 10.8% for white wine, from 6.5 to 10.8% for red wine, and from 4.7 to 16.5% for beer. Relative standard deviations for between-laboratories reproducibility (RSDR) ranged from 13.1 to 15.9% for white wine, from 11.9 to 13.6% for red wine, and from 15.2 to 26.1% for beer. HORRAT values were < or =0.4 for the 3 matrixes.     

Molecularly imprinted polymer‐based solid phase clean‐up for analysis of ochratoxin A in beer,red wine,and grape juice

A simple, reliable, and low‐cost method based on molecularly imprinted polymer as a selective sorbent of SPE was proposed for the determination of ochratoxin A (OTA) in beer, red wine, and grape juice by HPLC coupled with fluorescence detection (HPLC‐FLD). Samples were diluted with water and cleaned up with an AFFINIMIP® SPE OTA column. After washing and eluting, the analyte was analyzed by HPLC‐FLD. Under the optimized conditions, LOD and LOQ for OTA were 0.025 and 0.08 ng/mL, respectively. The recoveries of OTA from beer, red wine, and grape spiked at 0.1, 2, and 5 ng/mL ranged from 91.6 to 101.7%. Furthermore, after a simple regenerated procedure, the molecularly imprinted polymer based SPE column could be reused at least 14 times to achieve more than 80% recoveries of OTA in real samples. The developed method was applied to the detection of 30 beer, red wine, and grape juice samples and only four samples were contaminated by OTA with levels below the legal limits.     

多波长叠加近红外吸收光谱法直接测定酒精饮料中的乙醇

利用乙醇在１３８２ｎｍ，１６９１ｎｍ和１７３０ｎｍ处的吸光度值，采用多波长叠加近红外吸收光谱法测定乙醇的含量。结果表明，乙醇在０％～２４％（Ｖ／Ｖ）浓度范围内呈良好的线性关系；回归方程为： Ａ＝ ０． ０１７５４＋ ０． ０４７４７Ｃ；相关系数ｒ＝０． ９９９４。用该法可直接测定葡萄酒、啤酒和黄酒中乙醇的含量，６次平行测定的ＲＳＤ分别为；葡萄酒４．０％，啤酒２．５％，黄酒２．４％。回收率为９７．５％～１０５．０％，本方法具有操作简便，准确和快速等优点。     

Determination of ochratoxin A and T-2 toxin in alcoholic beverages by hollow fiber liquid phase microextraction and ultra high-pressure liquid chromatography coupled to tandem mass spectrometry

A new method for the determination of ochratoxin A and T-2 toxin in alcoholic beverages (wine and beer) by hollow fiber liquid microextraction was optimized. The extraction step was followed by ultra high-pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The extraction procedure was based on the extraction of mycotoxins from the sample to the organic solvent (1-octanol) immobilized in the fiber, and afterwards, they were desorbed in a mixture of acetonitrile/water (80:20, v/v) at pH 7 prior to chromatographic determination. Different variables affecting the extraction process such as organic solvent, salt content, extraction time and desorption solution were studied. The developed method was validated in wine and beer, using white wine and alcoholic beer as representative matrices for both types of samples. Relative recoveries higher than 70% were obtained for the selected mycotoxins. Good linearity (R² > 0.993) was obtained and quantification limits (0.02-0.09 μg L⁻¹) below European regulatory levels were achieved. Repeatability, expressed as relative standard deviation, was always lower than 12%, whereas interday precision was lower than 21%. The proposed method was applied to the analysis of several types of wines and beers and ochratoxin A was detected in a rosé wine at 1.1 μg L⁻¹.     

分散微固相萃取-超高效液相色谱-高分辨质谱法测定葡萄酒和啤酒中多菌灵和噻菌灵

基于强阳离子交换填料（PCX）,采用分散微固相萃取前处理技术,结合超高效液相色谱-四级杆-静电场轨道阱高分辨质谱联用技术,建立了一种快速测定葡萄酒和啤酒中多菌灵和噻菌灵的方法。通过对分散微固相萃取技术中PCX用量、洗脱溶剂中氨水的体积分数、乙腈的体积分数和洗脱体积的优化,实现了样品中多菌灵和噻菌灵的有效净化。经BEH C₁₈（50 mm×2.1 mm,1.7 μm）色谱柱分离后,通过静电场轨道阱质谱靶向单一离子监测（targeted single ion monitoring,tSIM）结合数据依赖的二级质谱扫描（data dependent tandem mass spectrometry,ddMS²）采集模式进行定性定量分析。待测物多菌灵和噻菌灵在一定浓度范围内均呈良好线性关系,相关系数R²≥0.9999。在葡萄酒和啤酒基质中,多菌灵和噻菌灵的检出限分别为0.02和0.01 μg/L,定量限分别为0.06和0.03 μg/L。在0.1、1.0、100 μg/L 3个添加水平下,多菌灵和噻菌灵的加标回收率分别为95.6%~110.2%和87.5%~102.8%,日内精密度（RSD_r）分别为1.8%~5.2%和1.3%~4.8%,日间精密度（RSD_R）分别为4.3%~8.7%和4.8%~9.4%。该方法快速、简便、灵敏,适用于葡萄酒和啤酒中多菌灵和噻菌灵的残留检测。     

Headspace solid-phase microextraction for the determination of volatile organic sulphur and selenium compounds in beers,wines and spirits using gas chromatography and atomic emission detection

A rapid and solvent-free method for the determination of eight volatile organic sulphur and two selenium compounds in different beverage samples using headspace solid-phase microextraction and gas chromatography with atomic emission detection has been developed. The bonded carboxen/polydimethylsiloxane fiber was the most suitable for preconcentrating the analytes from the headspace of the sample solution. Volumes of 20 mL of undiluted beer were used while, in the case of wines and spirits, sample:water ratios of 5:15 and 2:18, respectively, were used, in order to obtain the maximum sensitivity. Quantitation was carried out by using synthetic matrices of beer and wine, and a spiked sample for spirits, and using ethyl methyl sulphide and isopropyl disulphide as internal standards. Detection limits ranged from 8 ng L⁻¹ to 40 ng mL⁻¹, depending on the compound and the beverage sample analyzed, with a fiber time exposure of 20 min at ambient temperature. The optimized method was successfully applied to different samples, some of the studied compounds being detected at concentration levels in the 0.04–152 ng mL⁻¹ range.     

A survey of ochratoxin A and aflatoxins in domestic and imported beers in Japan by immunoaffinity and liquid chromatography.

Analyses of ochratoxin A (OTA) and aflatoxins (AFs) in 94 imported beer samples from 31 producing countries and in 22 Japanese beer samples were performed by immunoaffinity column and reversed-phase liquid chromatography (LC) with fluorescence detection. Recoveries of OTA from beer samples spiked at 25 and 250 pg/mL were 86.1 and 88.2%, respectively. Recoveries of AFs were 98.4 and 98.9%, 95.4 and 95.5%, 101.2 and 97.8%, and 98.9 and 96.0%, respectively, from beer samples spiked at 4.1 and 41 pg AF B1, 4.45 and 44.5 pg AF B2, 4.7 and 47 pg AF G1, and 4.65 and 46.5 pg AF G2/mL. Detection limits were 1.0 pg/mL for OTA, 0.5 pg/mL for AFs B1 and B2, and 1.0 pg/mL for AFs G1 and G2. OTA was detected in 86 (91.5%) of 94 imported beer samples at a mean level of 10.1 pg/mL and in 21 (95.5%) of 22 Japanese beer samples at a mean level of 12.5 pg/mL. AF B1 was detected in 11 of 94 imported beer samples at a level of 0.5-83.1 pg/mL and in 2 of 22 Japanese beer samples at 0.5 and 0.8 pg/mL. Except for one beer sample from Peru, the samples contaminated with AFs were also contaminated with OTA. Although OTA was detected in most samples from various countries, AFs were detected in the beer samples from only a limited number of countries where AF contamination might be expected to occur because of their warm climate.     

Determination of Ethanol in Alcoholic Drinks: Flow Injection Analysis with Amperometric Detection Versus Portable Raman Spectrometer

A flow injection analysis with integrated amperometric alcohol dehydrogenase biosensor and a handheld Mira‐DS Raman spectrometer have been compared for the determination of ethanol in different samples of alcoholic drinks. The biosensor was constructed from the commercial screen‐printed carbon electrode as amperometric transducer and covered by a thin layer comprising alcohol dehydrogenase, reduced single‐layer graphene oxide, rhodium(IV) dioxide, and glutaraldehyde. Both assemblies were tested on analysis of plum brandy, white rum, vodka, white and red wines, strong dark beer, and non‐alcoholic beer. The two principally different analytical methods were critically compared and some limitations found, especially in case of analysis of red wine and beers. Finally, some future improvements of both analytical tools under test outlined.     

Nickel Amperometric Detector Prepared by Electroless Deposition for Microchip Electrophoretic Measurement of Alcohols and Sugars

Nickel was deposited directly at the end of an electrophoretic glass microchip using an electroless deposition procedure leading to an attractive amperometric detector for sugars and alcohols. Such direct electroless deposition of nickel at the end of the separation chip greatly simplifies the preparation of on‐chip electrochemical detectors. Variables affecting the preparation and operation of the new detector are characterized and optimized. The integrated capillary electrophoresis‐electrochemical detection microsystem was evaluated for the separation of alcohols and sugars in connection to assays of different beer and wine samples. Linear calibration plots and favorable detection limits are found that meet the needs of real sample (wine and beer) analyses. This represents the first example of using nickel electrode and detecting alcohols on microchip platforms.