scholarly journals THE ROLE OF THIN LAYER CHROMATOGRAPHY AT CRIMINALISTIC INVESTIGATION OF OIL PRODUCTS BASED INFLAMMATORY MIXTURES

2019 ◽  
Vol 19 (1) ◽  
pp. 256-270
Author(s):  
V. Rudniev ◽  
O. Bui ◽  
A. Klimchuk
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Solvent System ◽  
Petroleum Products ◽  
Oil Products ◽  
Primary Study ◽  
Chromatography Method ◽  
Forensic Practice ◽  
Material Evidence ◽  
Layer Chromatography

The appearance and quality of the material evidence that comes to the study, often also not conducive to the use of complex methods of analysis. There are no separate techniques for forensic investigation of incendiary mixtures, and existing approaches to the study of petroleum products and fuels and lubricants do not allow the tasks set before the experts to be fully addressed. To determine the applicability of the thin layer chromatography method and to interpret its results for the examination of incendiary mixtures, forensic modeling of incendiary incendiary incendiary mixtures was conducted. The study revealed the possibilities and limitations of thin layer chromatography in the analysis of complex compositions, including those containing polymeric thickeners. The results were interpreted for use in forensic practice. The study was performed by TLC in an octane solvent system: benzene with the detection of colored zones in UV rays, with the manifestation of iodine vapors and the processing of chromatograms of 2% formaldehyde in sulfuric acid. The results of thin-layer chromatography characterize the main constituent components and can be used in the primary study of petroleum- based ignition mixtures in expert practice. The use of UV detection of colored zones on a chromatographic plate allows to assess in more detail the nature and composition of the mixture under study, including to identify distillate and residual oil products. Thin-layer chromatography can be recommended as a mandatory method of investigation for the ignition mixtures, which precedes the use of more complex Physics and Chemistry spectral and chromatographic approaches.

scholarly journals DETERMINATION OF FECES IN TRACES ON MATERIAL EVIDENCE BY THE METHOD OF ASCENDANT THIN LAYER CHROMATOGRAPHY

2019 ◽  
Vol 4 (4) ◽  
pp. 30-32 ◽  
Author(s):  
A. P. Chetvertnova ◽  
A. L. Fedorovtsev ◽  
N. S. Edelev
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Solvent System ◽  
Sectional Study ◽  
Pigment Composition ◽  
Physical Evidence ◽  
Material Evidence ◽  
Layer Chromatography ◽  
Positive Results

The article presents the results of a study of the pigment composition of feces in traces on material evidence by the method of thin-layer chromatography. The aim of the study was to develop a method for determining the presence of feces based on the detection of stercobilin. The objects of the study were samples of feces of adults without visible pathological changes in the liver, gallbladder, intestines in a sectional study, with a fence age of 3 days to 1 year. When using chromatography of fecal samples in the solvent system butanol-distilled water-glacial acetic acid (4:1:2) and subsequent processing with Ehrlich reagent positive results were obtained – the appearance of red stripes on chromatograms at Rf = 0,55–0,6, which indicates the presence of stercobilin. When studying the samples of meconium, blood, salvia, sweat, vaginal contents, and urine by this way, the reaction to the presence of stercobilin was negative. Thus, this method can be used in practice to determine the presence of feces in the traces on physical evidence.

OPTIMIZATION OF THIN LAYER CHROMATOGRAPHY METHODS FOR SEPARATION AND IDENTIFICATION OF ANTIDEPRESSANTS IN THEIR MIXTURE

2014 ◽  
Vol 21 (1) ◽  
pp. 11-15
Author(s):  
Daiva Kazlauskienė ◽  
Guoda Kiliuvienė ◽  
Palma Nenortienė ◽  
Giedrė Kasparavičienė ◽  
Ieva Matukaitytė
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Solvent System ◽  
Ammonia Solution ◽  
Relative Standard ◽  
Rf Values ◽  
Solvent Systems ◽  
Paroxetine Hydrochloride ◽  
Fluvoxamine Maleate ◽  
Layer Chromatography

By conducting the toxicological analysis it is meaningful to determine the analytical system that could identify simultaneously several medicinal preparations quickly and precisely. The purpose of this work was to create and validate the method of thin-layer chromatography that would be suitable to separate the components of antidepressant mixture (amitriptyline hydrochloride, paroxetine hydrochloride, sertraline hydrochloride, fluvoxamine maleate and buspirone hydrochloride) and to identify them. The system was validated with regard to the sensitivity, repetition of data, resistance and particularity. The solvent systems with potential of high separation of components in their mixture were created: acetonitrile, methanol, ammonia solution 25 percent (85:10:5); acetonitrile, methanol, ammonia solution 25 percent (75:20:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (50:45:5); dichlormethane, 1,4-dioxane, ammonia solution 25 percent (42:55:3); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (25:70:5); trichlormethane, 1,4-dioxane, ammonia solution 25 percent (60:36:4). One of the most suitable solvent systems for separation of the analyzed mixture (sertraline, amitriptyline, paroxetine, buspirone, fluvoxamine) was determined – acetonitrile, methanol, ammonia solution 25 percent (85:10:5). When this solvent system was used, the average Rf values of the analyzed compounds differed the most. Validation was conducted – the relative standard deviation (RSD, percent) of the average Rf value of the analyzed compounds varied from 0,6 to 1,8 percent and did not exceed the permissible error of 5 percent. The sensitivity of methodology was determined by assessing the intensity of the mixture’s spots on the chromatographic plate. The detection limit of buspirone was 0,0012 µg; sertraline – 0,0008 µg; amitriptyline – 0,0004 µg; fluvoxamine – 0,0004 µg; paroxetine – 0,0008 µg. The resistance of results to the changed conditions – it was determined that when the amounts of the solvents acetonitrile and methanol were increased or decreased to two milliliters, the average Rf values of the analyzed compounds did not change statistically significantly

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