Quantitative analysis of chlorpromazine by electron spin resonance (ESR) spectroscopy

A simple and sensitive method is described for quantitative analysis of chlorpromazine in blood, serum, urine and tissue homogenate. The chlorpromazine cation radical produced by adding perchloric acid and 2,3-dichloro-5,6-dicyano-p-benzoquinone to the sample can be detected by the ESR method at room temperature. The sensitivity limit is 10 ng, that is, 20 μl of the solution containing 0.5 μg chlorpromazine/ml. The time needed for the measurement is within 10 min. The chlorpromazine radical thus produced is very stable; for example, 95% of the radical was observed after 24 h. The advantage of this method is discussed by comparing with the ordinary spectrophotometry which requires the purification of the sample.     

Determination of paraquat in raw and formalin-fixed tissues by electron spin resonance (ESR) spectroscopy

ESR method was applied to determine paraquat levels in fresh and formalin-fixed tissues. Paraquat was converted to paraquat radical by adding sodium dithionite to tissue homogenates and detected by ESR. Paraquat levels of more than 0.2 micrograms/ml homogenate could be quantified with 0.1 ml of the homogenate. The use of manganese ions for standardization of paraquat signal enabled much more accurate ESR measurements because this ion was quite stable and its signal did not overlap that of paraquat. Even with tissues fixed in formalin, tissues paraquat levels were measureable after removing formalin from the tissue extract. This fact was verified by studying two cases; the tissues were kept in formalin for 1.5 years in case 1 and for 6.5 years in case 2. In both cases, the paraquat contents in tissues were 0.02-0.08 micrograms/g. In this way ESR is one of the most suitable methods in determining low levels of paraquat in tissues even after they were preserved in formalin for a long time.     

Determination of diquat in biological materials by electron spin resonance spectroscopy

An electron spin resonance (ESR) method already in use for the quantitative analysis of paraquat was applied to the analysis of diquat in blood, serum, urine, tissue homogenates and several drinks without purification of the samples. The diquat radical produced with ascorbic acid at alkaline pH was much more stable than that produced with the commonly used sodium dithionite. Radical decay in solutions covered with n-hexane was less than 5% after 60 min over a wide range of ascorbic acid concentrations. In 0.2 N NaOH solution 85% of the radicals was present even after 24 h. The limit of detection was 0.3 micrograms/ml and the required amount of sample was 0.1 ml. When both diquat and paraquat were present in a sample the diquat was first extracted with 1-butanol prior to the ESR measurement, because both species were converted to the radicals.     

Identification and quantitation of gamma-hydroxybutyrate (NaGHB) by nuclear magnetic resonance spectroscopy

The most common means of identification of gamma-hydroxybutyrate (NaGHB) involves using Fourier transform infrared spectroscopy (FTIR) or gas chromatography-mass spectrometry (GC-MS) of a suitable derivative. However, these methods may be complicated by possible shifts in chemical equilibrium between gamma-hydroxybutyric acid (GHB), GHB salts and the precursor lactone, gamma-butyrolactone (GBL). This paper addresses the technique of proton and carbon nuclear magnetic resonance spectroscopy (1H and 13C NMR) for the direct and accurate identification of GHB and GBL. The application of 1H NMR for GHB quantitation is also discussed.     

Determination of firing distance. Lead analysis on the target by atomic absorption spectroscopy (AAS)

This paper reports a method for the determination of the firing distance. Atomic absorption spectroscopy (AAS) was used to determine the lead (Pb) pattern around bullet holes produced by shots on test targets from the gun. Test shots were made with a Colt 38 Special at 5, 10, 20, 25, 30, 35, 40, 45, 50, 60, 80, and 100 cm target distance. The target was created with sheets of Whatman no. 1 paper on a polystyrene support. The target was subdivided into three carefully cut out rings (1, 2, and 3; with external diameters of 1.4 cm; 5 cm; 10.2 cm, respectively). Each sample was analyzed with graphite furnace AAS. Lead values analysis performed for each ring yielded a linear relation between the firing distance (cm) and the logarithm of lead amounts (microg/cm(2)) in definite target areas (areas 2 + 3): [ln dPb(2+3) = a(0) + a(1)l]; where dPb(2+3) = lead microg/cm(2) of area 2 + 3; a(0) and a(1) are experimentally calculated; l = distance in cm.     

Quantitative analysis of sharp-force trauma: an application of scanning electron microscopy in forensic anthropology.

Scanning electron microscopy (SEM) has occasionally been used by anthropologists and forensic scientists to look at morphological characteristics that certain implements leave on bone. However, few studies have addressed techniques or protocols for assessing quantitative differences between tool marks on bone made by different bladed implements. In this study, the statistical variation in cut mark width was examined between control and test samples on bone using a scalpel blade, paring knife, and kitchen utility knife. Statistically significant differences (p < .0005) were found between cut marks made by the same knife under control and test conditions for all three knife types used in the study. When the control sample and test samples were examined individually for differences in mean variation between knife types, significant differences were also found (p < .0005). While significant differences in cut mark width were found, caution should be used in trying to classify individual cut marks as being inflicted by a particular implement, due to the overlap in cut mark width that exists between different knife types. When combined, both quantitative and qualitative analyses of cut marks should prove to be more useful in trying to identify a suspect weapon. Furthermore, the application of SEM can be particularly useful for assessing many of these features.     

Estimation of the age of human bloodstains by electron paramagnetic resonance spectroscopy: long-term controlled experiment on the effects of environmental factors

In this study, we examined the efficacy and limitations of electron paramagnetic resonance (EPR) for estimating the age of human bloodstains. At 77K, human bloodstains give four striking EPR signals in the g=6.2 (g6), 4.3 (g4), 2.27 (H) and 2.005 (R) regions due to ferric high-spin, ferric non-heme, ferric low-spin and free radical species, respectively. We found that plotting double logarithms of the EPR intensity ratio of H/g4 versus days past bleeding gave a linear correlation up to 432 days with an error range within 25% of the actual number of days under controlled conditions. However, environmental factors such as differences of absorbent, light exposure and fluctuations of storage temperature affected the changes of these EPR-active compounds, which result in misestimation of the time since bleeding occurred. Therefore, one should take such factors into account in estimating the period since bleeding by this method.     

The specificity of electron impact mass spectroscopy for the identification of N-ethyl-1-phenylcyclohexylamine (PCE)

The electron impact mass spectrum of N-ethyl-1-phenylcyclohexylamine (PCE) was studied using both deuterium-labeled compounds and structurally related analogs. The deuterium-labeled compounds used were d2 . PCE with two deuterium atoms on the methylene carbon of the N-ethyl group, d3 . PCE with three deuterium atoms on the methyl carbon of the N-ethyl group, d4 . PCE with four deuterium atoms on the beta carbons of the cyclohexyl rings, and d5 . PCE with five deuterium atoms on the phenyl ring. Structurally related compounds used included the N,N-dimethyl, N-propyl, and cyclopentyl analogs. The identities of some major fragments and possible pathways leading to their formation are shown. Electron impact mass spectroscopy is shown to be a definitive test for the identification of PCE.     

Compositional analysis for identification of arson accelerants by electron ionization Fourier transform ion cyclotron resonance high-resolution mass spectrometry

Elemental compositions of each of 100 to 500 different constituents (i.e., every peak in a mass-to-charge ratio range, 50 < m/z < 300) of lighter fluid, kerosene, turpatine, gasoline, diesel fuel, and two brands of mineral spirits (and their weathered analogs) make possible direct identification of each accelerant in a experimental fire, based on electron ionization 6.0 Tesla Fourier transform ion cyclotron resonance (EI FT-ICR) ultrahigh resolution mass spectrometry. Septum injection of as little as 500 nL of accelerant into an all-glass heated inlet system yields definitive elemental compositions (molecular formulas) based on accurate (< +/-1 ppm average error) mass measurement alone. Extraction and EI FT-ICR mass analysis of fire debris from a controlled burn of a couch with simple (lighter fluid) and complex (turpatine) ignitable liquid yielded dozens of elemental compositions serving as a unique "fingerprint" for each petroleum product, despite the presence of up to 249 additional extracted matrix and pyrolysis components. Forty-five of 56 lighter fluid constituents and 126 of 133 turpatine constituents (not counting 13C-containing species) were identified in the debris from a fire staged for each respective accelerant.     

激光拉曼光谱对苯骈杂氮（堇）类药物的定性检测

目的 建立用拉曼光谱检测苯骈杂氮革类药物的定性方法.方法 利用激光拉曼光谱仪对10种苯骈杂氮革类药物进行检验.结果 10种苯骈杂氮（萆）类药物的主成分均能被拉曼准确检出.结论 该法能较好地对苯骈杂氮革类药物固体样品快速定性分析.     

A market study of green spray paints by Fourier transform infrared (FTIR) and Raman spectroscopy.

A market study of 40 different green spray paints was carried out using infrared (FTIR) and Raman spectroscopy. The infrared technique distinguished between the 12 main groups based on their binder and extender composition. After visual comparison of the spectra 22 subgroups were observed. Raman spectroscopy was also carried out on the 40 reference paints in order to determine the pigment content. Analyses were undertaken using two different excitation sources: Argon ion (514.5 nm) and Helium-Neon (632.8 nm). The first generated strong fluorescence for most of the samples and created eight groups. Using the red laser, 15 classes were observed. Finally, using an analytical sequence starting with infrared spectroscopy followed by Raman Helium-Neon and then by Raman Argon laser, most of the paints were differentiated. In this study infrared and Raman spectroscopy complemented each other. FTIR supplied information about the binder and some extenders, and Raman provided information on the main organic pigments present.     

The analysis of clingfilms by infrared spectroscopy and thermal desorption capillary gas chromatography.

An automated thermal desorption gas chromatography technique has been adapted to analyse traces of volatile compounds in proprietary food-wrapping films. Fourteen brands of polyvinylchloride film, seven brands of polyethylene film and one polyvinylidene chloride film were discriminated. Prior infrared analysis was used to identify the polymer type. The chromatograms showed minor changes in volatiles along the length of a roll of film and major changes in films exposed to daylight or in contact with cannabis resin.     

Proton nuclear magnetic resonance spectroscopy (NMR) methods for determining the purity of reference drug standards and illicit forensic drug seizures

A rapid, sensitive, accurate, precise, reproducible, and versatile method for determining the purity of reference drug standards and the routine analysis of illicit drugs and adulterants using proton (1H) Nuclear Magnetic Resonance (NMR) Spectroscopy is presented. The methodology uses a weighed sample dissolved in a deuterated solvent or solvent mixture containing a high purity internal standard. The NMR experiment employs 8 scans using a 45 second delay and 90 degrees pulse. In the determination of purity of reference standards, the number of quantitative determinations available is equal to the number of peak groups that are baseline resolved. The relative standard deviation (RSD) of these signals is usually < 1% for pure standards, and the results agree well with other purity determining methods. This method can also aid in the determination of correct molecular weight for standards containing an unknown number of waters of hydration or an unknown number of acids per drug in salts. Because the molar response for the hydrogen nucleus is 1 for all compounds, and since no separation media are used, only one linearity study is required to test a probe. In the presented study, the linearity of the NMR probe was determined using methamphetamine HCl dissolved in deuterium oxide (D2O) with maleic acid as the internal standard (5 mg) for a range of concentrations from 0.033 to 69.18 mg/ml with a resulting correlation coefficient of >0.9999 for all 6 methamphetamine peak groups. The spectra of complex illicit heroin, methamphetamine, MDMA, and cocaine samples are presented, as well as an extensive list of compounds, their solubilities and the solvent(s) and internal standard used.     

Spatially offset Raman spectroscopy (SORS) for the analysis and detection of packaged pharmaceuticals and concealed drugs

Spatially offset Raman spectroscopy (SORS) is a powerful new technique for the non-invasive detection and identification of concealed substances and drugs. Here, we demonstrate the SORS technique in several scenarios that are relevant to customs screening, postal screening, drug detection and forensics applications. The examples include analysis of a multi-layered postal package to identify a concealed substance; identification of an antibiotic capsule inside its plastic blister pack; analysis of an envelope containing a powder; and identification of a drug dissolved in a clear solvent, contained in a non-transparent plastic bottle. As well as providing practical examples of SORS, the results highlight several considerations regarding the use of SORS in the field, including the advantages of different analysis geometries and the ability to tailor instrument parameters and optics to suit different types of packages and samples. We also discuss the features and benefits of SORS in relation to existing Raman techniques, including confocal microscopy, wide area illumination and the conventional backscattered Raman spectroscopy. The results will contribute to the recognition of SORS as a promising method for the rapid, chemically specific analysis and detection of drugs and pharmaceuticals.     

A scanning electron microscopy and electron probe X-ray microanalysis (SEM-EPMA) of pink teeth

Samples of postmortem pink teeth were investigated by scanning electron microscopy and electron probe X-ray microanalysis. Fracture surfaces of the dentin in pink teeth were noticeably rough and revealed many more smaller dentinal tubules than those of the control white teeth. Electron probe X-ray microanalysis showed that the pink teeth contained iron which seemed to be derived from blood hemoglobin. The present study confirms that under the same circumstance red coloration of teeth may occur more easily in the teeth in which the dentin is less compact and contains more dentinal tubules.     

UPLC-MS/MS测定全血中的氯丙嗪

目的建立全血中氯丙嗪的UPLC-MS/MS分析方法。方法采用乙腈沉淀蛋白,以Waters ACQUITY UPLCBEH C18柱(2.1mm×50mm,1.7μm)分离,乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,正离子方式检测,多反应离子监测模式(MRM)。结果血液中氯丙嗪在1～100ng/mL范围内线形关系良好,检出限为0.01ng/mL,回收率为81.81%～89.36%,日内、日间精密度分别为9.3%、12.1%。结论本方法准确、快速,可用于全血中氯丙嗪的定性定量分析。     

Quantitative analysis of proinflammatory cytokines (IL-1beta, IL-6, TNF-alpha) in human skin wounds

Proinflammatory cytokines play an important role in the mediation of inflammation and trauma. They could be useful for the determination of vitality and wound age. In the present study, 144 human skin wounds due to sharp force were investigated. The material was collected during operations (N=96) and postmortem examinations (N=48). The wound age varied from several seconds or minutes to 9 days. Control skin was available in each individual. The tissue specimens were homogenized and extracted in a solution of PBS and protease inhibitors. Interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) were measured by quantitative ELISA analysis. Statistical evaluation was performed by the t-test using the quotients of levels (wound sample/control skin). In surgical specimens the cytokine levels revealed a clear tendency to increase with wound age. IL-1beta in early skin wounds (24 h, P<0.05). The quantitative analysis of proinflammatory cytokines in wound extracts can contribute to the determination of vitality and wound age, in particular in the very early post-traumatic interval (classic stab wounds).     

HLA DQ alpha typing of forensic specimens by amplification restriction fragment polymorphism (ARFP) analysis.

The alleles present at the HLA DQ alpha locus may be typed by either allele specific oligonucleotide (ASO) probing or by restriction mapping, referred to here as amplification restriction fragment polymorphism (ARFP) analysis. ASO typing relies upon hybridization principles, whereas ARFP typing relies upon restriction site analysis. Dot-blot ASO typings which are of doubtful interpretation may be directly checked by ARFP analysis. Aliquots of the PCR products amplified using the commercial Amplitype HLA DQ alpha system are digested with suitable restriction endonucleases. Electrophoresis, blotting and detection of biotin-labelled restriction fragments provides a sensitive and robust typing method suited to forensic analysis.     

The analysis of quaternary ammonium compounds in human urine by direct inlet electron impact ionization mass spectrometry.

An accurate and rapid screening test for nine quaternary ammonium compounds (suxamethonium chloride, pancuronium bromide, ambenonium chloride, benzethonium chloride, distigmine bromide, methylbenactyzium bromide, neostigmine bromide, propantheline bromide and pyridostigmine bromide) by direct inlet electron impact ionization mass spectrometry (DI/EI-MS) was investigated. Each compound was extracted from urine as an ion pair with KI3 into dichloromethane. The reliability of the identification of these compounds was verified by the mass chromatographic analysis of their characteristic fragment ions. The analysis of these drugs by DI/EI-MS could be performed within 5 min. The detection limits were between 20-150 ng/ml for the nine compounds. This method appears to be efficient, rapid and suitable as a screening procedure for the quaternary ammonium compounds found in urine.