The affect of tissue depth variation on craniofacial reconstructions

The consumption of synthetic drugs, generally known as designer drugs, has increased drastically in all parts of the world. Typical constituents of designer synthetic drugs are chemical substances derived from amphetamine but significant differences in effects caused and duration may result. In May, 2005, the civil state police of Sao Paulo seized thirty-one gelatinous capsules containing a very small quantity of a white powder inside (approximately 1.5 mg per capsule). This paper describes the analytical assays that were used to identify the seized material. Preliminary assays using colorimetric tests and high performance thin-layer chromatography indicated that the capsules content could be an amphetamine derivative. In the capillary zone electrophoresis assay, it was possible to observe that the analyzed material had basic characteristics. Mass spectrometry analysis revealed that the compound had the same molecular mass as 2,5-dimethoxy-4-bromoamphetamine (DOB) and its identity was confirmed through collision-induced dissociation (CID) experiments. Finally, the comparison of infrared sample spectrum with a spectra library provided further evidence of the DOB presence in the seized material. Although a reference standard material was not available, the information gathered from the different assays allowed the conclusion that the substance was, in fact, DOB, a substance with a powerful hallucinogenic action of proscribed use in the country and which was seized and identified for the first time in Brazil.     

莫达非尼药片的激光共聚焦显微拉曼光谱快速检验

目的建立莫达非尼药片的拉曼光谱快速定性检验方法。方法莫达非尼对照品和药片检材分别研磨后经拉曼光谱检验得到拉曼谱图。结果经比较,二者图谱一致,确定检出莫达非尼成分,结果可靠。结论莫达非尼药片在本文所述的条件下有较好的响应,峰型较好,峰位准确,同时药片中的淀粉等物质干扰较小。本文所建立的拉曼光谱检验方法,简便、高效、准确,可供一线执法、检验部门对查获的莫达非尼药片进行快速的定性检验。     

Surface-enhanced Raman spectroscopy for trace identification of controlled substances: Morphine, codeine, and hydrocodone

We obtain the normal Raman and surface-enhanced Raman spectrum of three controlled substances: morphine, codeine, and hydrocodone. The spectra are assigned with the aid of density functional theory. Because of rather intense fluorescence, normal Raman spectra suffer from poor signal-to-noise, even when differential subtraction techniques are employed. On the other hand, surface enhancement by Ag nanoparticles both enhances the Raman signal and suppresses the fluorescence, enabling far more sensitive detection and identification. We also present a set of discriminant bands, useful for distinguishing the three compounds, despite the similarities in their structures.     

Discrimination of phenethylamine regioisomers and structural analogues by Raman spectroscopy

In this study, the Raman spectra of 21 phenethylamines were obtained using far‐red excitation (785 nm). The distinguishing ability of Raman for phenethylamines, especially for phenethylamine regioisomers and structural analogues, was investigated. Here, the evaluation of a cross section of Raman spectra demonstrated that all types of phenethylamines were distinguishable, even for certain structural analogues with high spectrum similarity. Raman exhibited high distinguishing ability for phenethylamine regioisomers that differ in the substitution position of halogen, methoxy, alkyl, or other substituted groups; as well as for structural analogues containing different groups, such as furanyl, 2,3‐dihydrofuranyl, halogen, and alkyl substituted at the same position. The Raman spectra for homologues with differences in only a methyl group were found to be highly similar; however, their spectra demonstrated small but detectable differences. Four analogue mixtures and 59 seized samples were also analyzed to study the practical use of the Raman method in forensic field. 95% of the seized samples were correctly identified, which significantly validated the ability of Raman method in identifying the correct isomers. Accordingly, this study provides a non‐destructive, high‐throughput and minimal sample preparation technique for the discrimination of phenethylamines.     

NIR analysis of cellulose and lactose--application to ecstasy tablet analysis

Cellulose and lactose are the most frequently used excipients in illicit ecstasy production. The aim of this project was to use near infrared reflectance spectroscopy (NIRS) for the determination of the different chemical forms of these two substances, as well as for the differentiation of their origin (producer). It was possible to distinguish between the different chemical forms of both compounds, as well as between their origins (producers), although within limits. Furthermore, the possibilities to apply NIR for the analysis of substances such as found in illicit tablets were studied. First, a few cellulose and lactose samples were chosen to make mixtures with amphetamine at three degrees of purity (5, 10 and 15%), in order to study the resulting changes in the spectra as well as to simultaneously quantify amphetamine and identify the excipient. A PLS2 model could be build to predict concentrations and excipient. Secondarily, the technique was to be applied to real ecstasy tablets. About 40 ecstasy seizures were analysed with the aim to determine the excipient and to check them against each other. Identification of the excipients was not always obvious, especially when more than one excipient were present. However, a comparison between tablets appeared to give groups of similar samples. NIR analysis results in spectra representing the tablet blend as a whole taking into account all absorbing compounds. Although NIRS seems to be an appropriate method for ecstasy profiling, little is known about intra- and intervariability of compression batches.     

Identification of Different Forms of Cocaine and Substances Used in Adulteration Using Near‐infrared Raman Spectroscopy and Infrared Absorption Spectroscopy

Identification of cocaine and subsequent quantification immediately after seizure are problems for the police in developing countries such as Brazil. This work proposes a comparison between the Raman and FT‐IR techniques as methods to identify cocaine, the adulterants used to increase volume, and possible degradation products in samples seized by the police. Near‐infrared Raman spectra (785 nm excitation, 10 sec exposure time) and FT‐IR‐ATR spectra were obtained from different samples of street cocaine and some substances commonly used as adulterants. Freebase powder, hydrochloride powder, and crack rock can be distinguished by both Raman and FT‐IR spectroscopies, revealing differences in their chemical structure. Most of the samples showed characteristic peaks of degradation products such as benzoylecgonine and benzoic acid, and some presented evidence of adulteration with aluminum sulfate and sodium carbonate. Raman spectroscopy is better than FT‐IR for identifying benzoic acid and inorganic adulterants in cocaine.     

Characteristics and trends of 3,4-methylenedioxymethamphetamine (MDMA) tablets found in Taiwan from 2002 to February 2005

One hundred and eighty-one 3,4-methylenedioxymethamphetamine (MDMA) containing tablets were sampled from confiscated drugs received by the Taiwan National Bureau of Controlled Drugs for testing from 2002 to February 2005. Sample tablets demonstrated various colors and logos. The appearances, contents of MDMA and other components in these tablets were analyzed in order to understand the characteristics and trends of MDMA use. Samples were analyzed using GC-MS methodology. Deuterated internal standards were used for drug quantification. The MDMA contents varied from 16 to 193 mg/tablet. 66-71% of the tablets seized each year contained only MDMA, and the content of MDMA in MDMA only tablets varied from 89 to 133 mg/tablet. There was a decreasing trend in MDMA content in these tablets over time. Other components commonly found besides MDMA included caffeine (18%), methamphetamine (7%), 3,4-methylenedioxyethylamphetamine (MDEA) (7%) and amphetamine (4%). 3,4-Methylenedioxyamphetamine (MDA), ketamine, ephedrine, diazepam, chlorzoxazone and nicotinamide were also detected. During the study period, the number of other drugs found as well as the combinations of different drugs detected in these tablets increased.     

Investigation of the new possibility of mathematical processing of Raman spectra for dating documents

The use of spectral analysis methods to determine the age of writing inks is an important forensic task. However, the use of spectral data for this purpose has a number of limitations and difficulties. This paper considers the application of the Raman spectroscopy method to an urgent forensic task. The known mechanisms of dye degradation are analyzed; Raman bands are identified that are related to the age of the sample. In a sample of 5 randomly selected writing inks, temporary markers were identified. Narrow sections of Raman spectra containing characteristic lines were used for analysis. It was shown that processing narrow sections of the Raman spectra using the PCA chemometric method allowed the separation of writing inks into groups (clusters) corresponding to different creation intervals.     

Quantification of the amphetamine content in seized street samples by Raman spectroscopy

A Raman spectroscopy method for determining the drug content of street samples of amphetamine was developed by dissolving samples in an acidic solution containing an internal standard (sodium dihydrogen phosphate). The Raman spectra of the samples were measured with a CDD-Raman spectrometer. Two Raman quantification methods were used: (1) relative peak heights of characteristic signals of the amphetamine and the internal standard; and (2) multivariate calibration by partial least squares (PLS) based on second derivative of the spectra. For the determination of the peak height ratio, the spectra were baseline corrected and the peak height ratio (h(amphetamine at 994 cm(-1) )/h(internal standard at 880 cm(-1) )) was calculated. For the PLS analysis, the wave number interval of 1300-630 cm(-1) (348 data points) was chosen. No manual baseline correction was performed, but the spectra were differentiated twice to obtain their second derivatives, which were further analyzed. The Raman results were well in line with validated reference LC results when the Raman samples were analyzed within 2 h after dissolution. The present results clearly show that Raman spectroscopy is a good tool for rapid (acquisition time 1 min) and accurate quantitative analysis of street samples that contain illicit drugs and unknown adulterants and impurities.     

Quantitative Analysis of Sildenafil and Tadalafil in Various Fake Drugs Recently Distributed in Korea

Abstract: Illicit distribution of various illicit or counterfeit drugs containing sildenafil and tadalafil has increased and caused noticeable problems in Korea. This study has been performed to determine the content range of sildenafil and tadalafil in various fake drugs. Among the illicit or counterfeit drugs seized by Korean authorities, 105 exhibits were used for the quantification. HPLC–UV analysis of methanol extractions was used for separation and quantitation of the two target compounds. The most abundant type of fake drug was counterfeit Viagra^® tablets. Sildenafil was found in 73 exhibits, and tadalafil was found in seven exhibits. Twenty‐five exhibits out of the 105 contained both sildenafil and tadalafil. The contents of sildenafil ranged from 4.3 to 453.2 mg; for tadalafil, the range was 2.2–40.4 mg. The proportion of cases of having more than 100 mg of sildenafil was 50% and 78% had more than 20 mg of tadalafil.     

Trace elemental analysis of drugs of abuse using synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

Synchrotron radiation total reflection X-ray fluorescence spectroscopy (SR-TXRF) was utilized to analyze various trace elements in small amounts of drugs of abuse. Sample amounts of 1 microL solutions containing 10 microg of drugs (methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine, cocaine, and heroin) were spotted on silicon wafers for direct analysis. In addition, a leaflet of marijuana was set directly on a silicon wafer, and opium in the form of a soft lump was smeared on another silicon wafer for analysis. In these experiments, about 10 pg of contaminant elements could be detected. For example, in a seized methamphetamine sample, iodine was found, which could be indicative of synthetic route. In seized 3,4-methylenedioxymethamphetamine samples, variable amounts of phosphorus, calcium, sulfur, and potassium were found, which could not be detected in a control 3,4-methylenedioxymethamphetamine sample. For marijuana and opium, two spectral patterns were obtained that were far different from each other and could be easily discriminated. Using SR-TXRF, pg amounts of each trace element in 10 microg of various drugs can be easily detected, which is not the case either for a standard TXRF experimental system or for other elemental analysis techniques.     

Evaluation and classification of fentanyl-related compounds using EC-SERS and machine learning

Multiple analytical techniques for the screening of fentanyl-related compounds exist. High discriminatory methods such as GC–MS and LC–MS are expensive, time-consuming, and less amenable to onsite analysis. Raman spectroscopy provides a rapid, inexpensive alternative. Raman variants such as electrochemical surface-enhanced Raman scattering (EC-SERS) can provide signal enhancements with 10¹⁰ magnitudes, allowing for the detection of low-concentration analytes, otherwise undetected using conventional Raman. Library search algorithms embedded in instruments utilizing SERS may suffer from accuracy when multicomponent mixtures involving fentanyl derivatives are analyzed. The complexing of machine learning techniques to Raman spectra demonstrates an improvement in the discrimination of drugs even when present in multicomponent mixtures of various ratios. Additionally, these algorithms are capable of identifying spectral features difficult to detect by manual comparisons. Therefore, the goal of this study was to evaluate fentanyl-related compounds and other drugs of abuse using EC-SERS and to process the acquired data using machine learning—convolutional neural networks (CNN). The CNN was created using Keras v 2.4.0 with Tensorflow v 2.9.1 backend. In-house binary mixtures and authentic adjudicated case samples were used to evaluate the created machine-learning models. The overall accuracy of the model was 98.4 ± 0.1% after 10-fold cross-validation. The correct identification for the in-house binary mixtures was 92%, while the authentic case samples were 85%. The high accuracies achieved in this study demonstrate the advantage of using machine learning to process spectral data when screening seized drug materials comprised of multiple components.     

Raman Spectroscopic Differences between Ephedrine and Pseudoephedrine

Ephedrine (EPH) and pseudoephedrine (PSE) were studied by micro‐Raman spectroscopy and UV resonance Raman spectroscopy excited at 785 and 360 nm, respectively. Raman bands at approximately 245 and 410 cm^?1 for ephedrine have apparent differences from the same bands at approximately 215, 265, 350, 450, and 555 cm^?1 for pseudoephedrine, and these differences can be applied to distinguish between EPH and PSE. Additionally, density functional theory was used for the Raman calculations to obtain results identical to the experimental spectra. This work is expected to expand the applications of Raman spectroscopy in forensic science.     

Rapid and simple method for direct determination of several amphetamines in seized tablets by GC--FID

A simple and rapid method for direct simultaneous determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA) and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in seized tablets was developed using gas chromatography with flame ionization detection. Separation of all six underivatized amphetamines, including diphenylamine as internal standard, was performed in about 6 min, using SPB-50 capillary column. Amphetamine and methamphetamine eluted with negligible tailing while the other amphetamines had highly symmetrical peaks. Sensitivity per component on-column was in the nanogram range, and reproducibility from 2.6 to 6.6% at low concentration (2.4 microg/mL) and from 1.2 to 2.6% at high (70 microg/mL) concentration. The method has a wide linear range, from Limit of detection (LOD) to almost 200 microg/mL, thus allowing analysis of different samples across a wide range of possible concentrations of amphetamines. This simple, fast and precise method using gas chromatography--flame ionization detector (GC--FID), in conjunction with other methods (TLC, IR, HPLC), can be used for identification of amphetamines and direct determination in seized tablets, especially in laboratories with heavy workload.     

Analysis of Ecstasy Tablets Using Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection

A method for the identification of 3,4‐methylenedioxymethamphetamine (MDMA) and meta‐chlorophenylpiperazine (mCPP) was developed employing capillary electrophoresis (CE) with capacitively coupled contactless conductivity detection (C⁴D). Sample extraction, separation, and detection of “Ecstasy” tablets were performed in <10 min without sample derivatization. The separation electrolyte was 20 mm TAPS/Lithium, pH 8.7. Average minimal detectable amounts for MDMA and mCPP were 0.04 mg/tablet, several orders of magnitude lower than the minimum amount encountered in a tablet. Seven different Ecstasy tablets seized in Rio de Janeiro, Brazil, were analyzed by CE‐C⁴D and compared against routine gas chromatography‐mass spectrometry (GC‐MS). The CE method demonstrated sufficient selectivity to discriminate the two target drugs, MDMA and mCPP, from the other drugs present in seizures, namely amphepramone, fenproporex, caffeine, lidocaine, and cocaine. Separation was performed in <90 sec. The advantages of using C⁴D instead of traditional CE‐UV methods for in‐field analysis are also discussed.     

基于拉曼光谱的血液遗留时间研究与模型预测

目的针对犯罪现场血液遗留时间的判断问题,实验以不同遗留时间的血液为研究对象,建立基于拉曼光谱的血液遗留时间的辨别方法。方法采集遗留时间为0.5h~240h的指尖血液样本,获取其拉曼光谱数据,经校正和平滑处理后,对数据进行归一化。利用RSD值评价光谱的稳定性,选取前10个主成分和6个重要波段分别建立模型,利用预测集测试模型效果。结果相同遗留时间血液的拉曼光谱具有较好的稳定(RSD<0.2),不同遗留时间血液的拉曼光谱在680cm^-1等6个波段有明显的强度变化。前10个主成分建立的PLSR模型,其r²=0.9927。6个重要波段建立的PLSR模型,预测集效果r²=0.8797。结论利用拉曼光谱结合建模分析是一种无损快速的评估血液遗留时间的方法。     

激光共聚焦拉曼光谱技术在烟火药检验中的应用

目的建立微量烟火药的无损检验方法。方法利用激光共聚焦拉曼光谱技术对烟火药进行检验。结果烟火药的不同组分具有不同的拉曼特征散射峰。结论利用激光共聚焦拉曼光谱技术可以对烟火药中的不同组分进行检验,通过成像技术可得到不同组分的分布信息,该方法具有检验灵敏度高、无需样品制备、无损检材等优点。     

Fourier transform infrared/Raman differentiation and characterization of cis- and trans-2,5-dimethoxy-4,beta-dimethyl-beta-nitrostyrenes: precursors to the street drug STP.

Fourier transform Raman and infrared spectra of pure cis(Z)- and trans(E)-2,5-dimethoxy-4,beta-dimethyl-beta-nitrostyrene (precursors of the psychotomimetic street drug STP or DOM) were recorded in the solid state. The spectra show characteristic features of the ethylene moiety and of the aryl and nitro substituents which permit ready differentiation and identification of these isomers. A very strong Raman line at 1670 cm-1 from the cis isomer for the C=C stretching mode, in comparison with a strong Raman line at 1641 cm-1 for the trans isomer, affords primary differentiation of these substances. A second characteristic, of both the Raman and infrared (IR) spectra, is that the frequency of the strong symmetric nitro (NO2) stretching band is about 40 cm-1 higher in the cis (1346 cm-1) than the trans isomer (1301 cm-1). All major IR and Raman bands are reported and given vibrational assignments.     

Characterization of Blue Pigments Used in Automotive Paints by Raman Spectroscopy

Micro‐Raman spectroscopy was applied to forensic identification of pigments in paint chips and provided differentiation between paint samples. Sixty‐six blue automotive paint samples, 26 solid and 40 metallic were examined. It was found that the majority of the collected Raman spectra provided information about the pigments present. However, in some cases, fluorescence precluded pigment identification. Using laser excitation at longer wavelengths or pretreatment to effect photobleaching often resulted in reduced fluorescence, particularly for solid color samples, and allowed pigment identification. The examined samples were compared pairwise taking into account number, location, and intensity of absorption bands in their infrared spectra. The estimated discrimination power ranged from 97% for solid paint samples to 99% for metallic paint samples.