排序方式: 共有42条查询结果,搜索用时 15 毫秒
1.
有机磷农药薄层色谱溴酚蓝显色法的改进 总被引:1,自引:0,他引:1
目的对有机磷农药薄层色谱溴酚蓝显色法进行改进,使该检验方法更完善。方法采用薄层色谱溴酚蓝—柠檬酸显色。结果显色背景呈纯正的浅黄色,并且颜色稳定。结论该方法操作简单、快速、检测灵敏度高。 相似文献
2.
3.
4.
5.
An evaluation of matching unknown writing inks with the United States International Ink Library 总被引:2,自引:0,他引:2
Laporte GM Arredondo MD McConnell TS Stephens JC Cantu AA Shaffer DK 《Journal of forensic sciences》2006,51(3):689-692
Utilizing a database of standards for forensic casework is a valuable resource. Undoubtedly, as more standards (and corresponding information about the specimens) are collected, there is a greater certainty of identification when a questioned and a known item cannot be distinguished after a series of analyses. The United States Secret Service and the Internal Revenue Service National Forensic Laboratory jointly maintain the largest known forensic collection of writing inks in the world, which is comprised of over 8500 ink standards collected worldwide, dating back to the 1920s. This study was conducted to evaluate the reliability of matching arbitrarily purchased pens with known inks from a database. One hundred pens were randomly obtained from a variety of sources and their respective ink compositions were compared with standards. Eighty-five of the inks were determined to be suitable for comparison utilizing optical examinations and thin-layer chromatography. Three of the inks did not match any of the specimens on record; one of these inks was similar to an ink from an identical brand of pen that was in the database, but had a modified formulation. 相似文献
6.
Eiichi Mikami Tsutomu Ohno Hiroshi Matsumoto 《Forensic Science International Supplement Series》2002,130(2-3):140-146
An easily available, simultaneous identification/determination procedure for phentolamine (PHE) and sildenafil (SIL) in adulterated dietary supplements was established by using a combination of three different analytical methods; thin-layer chromatography (TLC), liquid chromatography–mass spectrometry (LC/MS) and a high-performance liquid chromatography (HPLC)/photo-diode-array. The sample solution for TLC was applied to silica gel 60 F254 plates with chloroform/ammonia solution (28)/methanol (70:5:3, lower layer) and chloroform/diethylamine/methanol (15:3:2) as the developing solvent. Spots were located under UV radiation at 254 nm. Mass spectra of PHE and SIL by LC/MS were investigated with electrospray ionization (ESI) interface, under both positive and negative ion mode. The HPLC analysis was performed on a column of Wakosil 5C18 (4.6 mm×150 mm, 5 μm) with water/methanol/acetonitrile/triethylamine (580:250:170:1) adjusted with phosphoric acid to pH 3.0 as the mobile phase, and the effluent was monitored with a photo-diode-array detector. Quantitative HPLC analysis of PHE and SIL were detected at 280 nm. When this procedure was applied to commercial soft drinks, PHE and SIL were identified and determined at a concentration of 17 mg PHE and 44 mg SIL per bottle, respectively. The procedure described here is available for the screening of PHE and SIL in adulterated supplements. 相似文献
7.
This paper deals with the police officer's or police doctor's ability to find drivers under the influence of drugs. We have also studied whether the protocol on the driver's previous histories of drug intake is useful for directing the chemist in his analytical approach to revealing intoxicants in the suspects' body fluids. A comprehensive procedure for screening traffic-hazardous drugs in the urine was found necessary and is described. By using this method, we have studied the incidence of drunken drivers with detectable medicinal or illicit agents. The results demonstrate that 91% of those drivers found by the officer or doctor of the police to be on intoxicants other than ethanol, carried some kind of traffic-hazardous drug in their body fluids, and that the doctor was a better judge than the police in identifying these offenders. By using a series of chemical methods for drug screening, we found that every third driver suspected of drunken driving due to ethanol, but not to other intoxicants, held some kind of a traffic-hazardous drug substance in his urine; benzodiazepines and cannabinoids were the most common findings. The data imply that 34% of these suspects revealed their intakes of traffic-dangerous intoxicants. We conclude that the judgements of both the officer and doctor of the police are needed for an efficacious detection of drivers under the influence of drugs. Moreover, the results infer that the chemist has to screen for intoxicants to reveal these in a suspect driver. We also conclude that drugs, particularly the benzodiazepines or cannabinoids, may be commonly encountered in drunken drivers, suspected of being inebriated by ethanol but no other toxicants. 相似文献
8.
Kato N Fujita S Ohta H Fukuba M Toriba A Hayakawa K 《Journal of forensic sciences》2008,53(6):1367-1371
A rapid and sensitive method for the detection of six methylenedioxylatedphenethylamines, 3,4-methylenedioxymethamphetamine (MDMA); 3,4-methylenedioxyamphetamine; 3,4-methylenedioxyethylamphetamine; N-methyl-1-(3,4-methylenedioxyphenyl)-2-butamine; N-methyl-1-(3,4-methylenedioxyphenyl)-3-butamine; and 3,4-methylenedioxydimethylamphetamine, by thin-layer chromatography with fluorescence detection is proposed. These compounds form fluorophores on the developing plate following spraying with a reagent consisting of sodium hypochlorite, potassium hexacyanoferrate (III), and sodium hydroxide, and heating for 3 min at 100 degrees C. Blue fluorescent spots were observed under ultraviolet light in a wavelength range of 250-400 nm. The detection limits for MDMA and the above related compounds were 50 ng. The proposed method was effectively applied to the detection of MDMA in urine samples. 相似文献
9.
Application of citric acid/acetic anhydride reagent (CAR), a colour reagent selective for tertiary amines in solution, improves detection of abused tertiary amino drugs on the TLC plate. The plate is pretreated by a brief immersion in phosphoric acid/acetone solution to suppress colouration. After suppressing, the plate is sprayed with CAR and heated at 100 degrees C, causing tertiary amines to turn red purple within 3 minutes. The sensitivity of this new CAR method is 2.5 to 15-times greater than that of conventional detection with Dragendorff reagent for some of the tertiary amines dimethylamphetamine, methylephedrine, levomepromazine, chlorpromazine, caffeine, theophylline, theobromine and nicotine. This present method provides rapid TLC detection of abused tertiary amino drugs such as phenethylamine, phenothiazine, xanthine derivative, nicotine and narcotics. 相似文献
10.