The Initial Changes of Fat Deposits During the Decomposition of Human and Pig Remains

Abstract:  The early stages of adipocere formation in both pig and human adipose tissue in aqueous environments have been investigated. The aims were to determine the short-term changes occurring to fat deposits during decomposition and to ascertain the suitability of pigs as models for human decomposition. Subcutaneous adipose tissue from both species after immersion in distilled water for up to six months was compared using Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry and inductively coupled plasma-mass spectrometry. Changes associated with decomposition were observed, but no adipocere was formed during the initial month of decomposition for either tissue type. Early-stage adipocere formation in pig samples during later months was detected. The variable time courses for adipose tissue decomposition were attributed to differences in the distribution of total fatty acids between species. Variations in the amount of sodium, potassium, calcium, and magnesium were also detected between species. The study shows that differences in total fatty acid composition between species need to be considered when interpreting results from experimental decomposition studies using pigs as human body analogs.     

Chlorinated Opium Alkaloid Derivatives Produced by the Use of Aqueous Sodium Hypochlorite During the Clandestine Manufacture of Heroin

Abstract:  A clandestine chemist was observed producing heroin from crude morphine utilizing a solution of sodium hypochlorite during the process. Numerous chlorinated opium alkaloid derivatives were created when the morphine acetylation reaction was quenched and neutralized with a solution of sodium hypochlorite and ammonium hydroxide. Four of these compounds, 1-chloroheroin, 1-chloroacetylcodeine, 1-chloro-O⁶-monoacetylmorphine, and 2'-chloropapaverine, were characterized via preparative isolation, gas chromatography/mass spectrometry, nuclear magnetic resonance spectroscopy, and independent synthesis. These chlorinated derivatives were formed via electrophilic aromatic substitution with free chlorine during the illicit process. Although no illicit heroin exhibits containing these compounds have been observed in seizures to date, mass spectral data are provided for several of these compounds for their identification should they be seen within future seizures of illicit heroin.     

Characterization of Undigested Particulate Material Following Microwave Digestion of Recycled Document Papers

Abstract:  Recycled document paper was microwave digested in a solution of HNO₃ and H₂O₂ prior to analysis by inductively coupled plasma mass spectrometry (ICP-MS) to determine the trace elemental concentrations within the paper. Undigested particulate material was observed and subsequently characterized as a mixture of kaolin (clay) and TiO₂ by Fourier transform infrared spectroscopy and X-ray diffraction spectroscopy. The effect of the particulate material on the elemental concentrations was then investigated. Paper samples were completely digested in hydrofluoric acid (HF) and element concentrations determined in the HF and HNO₃/H₂O digests were statistically compared using Student's t -test (95% confidence limit). Statistical differences in element concentrations between the two digests were observed for only four elements and there was no evidence of element adsorption by the particulate material. Hence, the HNO₃/H₂O₂ digestion proved sufficient to digest paper for ICP-MS analysis, eliminating the need to use the hazardous and corrosive HF matrix.     

Some Examples of Applications of a Microthermal Desorption Device in the Forensic Laboratory

Abstract:  Several applications of a microthermal desorption device for analysis of small forensic samples are presented. The method uses a solid phase microextraction holder with the fiber removed. In addition to samples of inks on paper, this device was successfully used for analysis of toners, various stains on bank notes, and lipstick stains on paper. Other small items encountered in a forensic science laboratory were also analyzed: particles of smokeless powder, particles of coffee, and automotive clear topcoat layer. The desorbed compounds were analyzed by gas chromatography with a flame ionization detector or by gas chromatography–mass spectrometry. This device can be used in connection with any kind of gas chromatograph. By selection of different injector temperatures, fractionated thermal desorption of samples is achieved. The procedure was demonstrated on samples of ballpoint pen ink of various age.     

The Stable Isotope Ratios of Marijuana. II. Strontium Isotopes Relate to Geographic Origin

Abstract:  Effectively addressing marijuana trade is aided by understanding marijuana geographic sources. We analyzed the ⁸⁷Sr/⁸⁶Sr of marijuana samples grown in 79 counties across the United States to determine if a primary geologic signal is retained in marijuana, which could therefore be useful for geographic sourcing. The marijuana results were compared with modeled bedrock ⁸⁷Sr/⁸⁶Sr values based on ⁸⁷Rb decay rates and a generalized geologic map of the U.S.A. A significant correlation was observed between marijuana ⁸⁷Sr/⁸⁶Sr and modeled bedrock ⁸⁷Sr/⁸⁶Sr. Although values clustered near the 1:1 relationship, there was a predominance of positive anomalies, perhaps attributable to carbonate bedrock. A small number of negative anomalies were also observed, which were generally associated with granitic bedrocks. These results suggest that strontium isotopes in marijuana record the geographic origins of marijuana, and that refinement of the base strontium map (or strontium isoscape) and improved understanding of other strontium sources would be productive.     

Validation of the Direct Analysis in Real Time Source for Use in Forensic Drug Screening

Abstract:  The Direct Analysis in Real Time (DART) ion source is a relatively new mass spectrometry technique that is seeing widespread use in chemical analyses world-wide. DART studies include such diverse topics as analysis of flavors and fragrances, melamine in contaminated dog food, differentiation of writing inks, characterization of solid counterfeit drugs, and as a detector for planar chromatography. Validation of this new technique for the rapid screening of forensic evidence for drugs of abuse, utilizing the DART source coupled to an accurate mass time-of-flight mass spectrometer, was conducted. The study consisted of the determination of the lower limit of detection for the method, determination of selectivity and a comparison of this technique to established analytical protocols. Examples of DART spectra are included. The results of this study have allowed the Virginia Department of Forensic Science to incorporate this new technique into their analysis scheme for the screening of solid dosage forms of drugs of abuse.     

The Analysis of Black Powder Substitutes Containing Ascorbic Acid by Ion Chromatography/Mass Spectrometry*†

Abstract: Black powder substitutes containing ascorbic acid are a group of low explosives that utilize ascorbic acid as the fuel. The analysis of these powders is complicated by the degradation of ascorbic acid which occurs rapidly in solution and may also occur as the powder ages. Aqueous extracts of both intact powders and postblast residues were analyzed by an existing ion chromatography/mass spectrometry (IC/MS) method used at the Bureau of Alcohol, Tobacco, Firearms and Explosives. Results have shown that while ascorbic acid itself is not detected in this method, its diagnostic degradation products (threonic acid, monohydrated diketogulonic acid, and oxalic acid) can be identified. In addition, anions from the inorganic oxidizers (perchlorate and nitrate) and combustion products such as chloride, chlorate, and nitrite, can be identified within the same experiment. While this IC/MS method shows promise, future modifications are necessary because of limitations in identifying threonate in postblast residues, as well as coeluting compounds observed in postblast residues.     

Effect of Gas Chromatography Temperature Program on the Association and Discrimination of Diesel Samples*†

Abstract: Five diesel samples were analyzed by gas chromatography–mass spectrometry (GC‐MS) using six GC temperature programs, aiming to investigate the effect of temperature program on association and discrimination of the samples. Temperature programs varied by ramp rate and incorporated one‐ or two‐step temperature ramps. Pearson product moment correlation coefficients and principal components analysis were used to evaluate differences in discrimination among the diesel samples afforded by each temperature program, based on the total ion chromatogram (TIC) and selected extracted ion profiles (EIPs). Association of diesel replicates and discrimination among samples based on the TIC and aromatic EIP were similar for all temperature programs based on scores plots. The alkane EIP was not useful in discriminating samples regardless of temperature program, because of similar alkane content of the diesel samples. The association and discrimination of diesel samples was largely unaffected by temperature programs that incorporated one‐ or two‐step temperature ramps.     

Forensic Analysis of Explosives Using Isotope Ratio Mass Spectrometry (IRMS)—Part 2: Forensic Inter-Laboratory Trial: Bulk Carbon and Nitrogen Stable Isotopes in a Range of Chemical Compounds (Australia and New Zealand)

Abstract:  Comparability of data over time and between laboratories is a key issue for consideration in the development of global databases, and more broadly for quality assurance in general. One mechanism that can be utilized for evaluating traceability is an inter-laboratory trial. This paper addresses an inter-laboratory trial conducted across a number of Australian and New Zealand isotope ratio mass spectrometry (IRMS) laboratories. The main objective of this trial was to determine whether IRMS laboratories in these countries would record comparable values for the distributed samples. Four carbon containing and four nitrogen containing compounds were distributed to seven laboratories in Australia and one in New Zealand. The laboratories were requested to analyze the samples using their standard procedures. The data from each laboratory was evaluated collectively using International Standard ISO 13528 ( Statistical methods for use in proficiency testing by inter-laboratory comparisons ). "Warning signals" were raised against one participant in this trial. "Action signals" requiring corrective action were raised against four participants. These participants reviewed the data and possible sources for the discrepancies. This inter-laboratory trial was successful in providing an initial snapshot of the potential for traceability between the participating laboratories. The statistical methods described in this article could be used as a model for others needing to evaluate stable isotope results derived from multiple laboratories, e.g., inter-laboratory trials/proficiency testing. Ongoing trials will be conducted to improve traceability across the Australian and New Zealand IRMS community.     

Anion Identification via Complexation with meso‐octamethylcalix(4)pyrrole and Detection Using Electrospray Ionization Mass Spectrometry*

Abstract: The routine identification of controlled substances and adulterants during forensic chemistry analysis often involves the identification of counter ions or salt forms present in an exhibit. Here, the use of the compound meso‐octamethylcalix(4)pyrrole (C4P) during salt‐form identification analysis is presented. C4P is a commercially‐available, anion‐binding agent that can be reacted with a controlled substance or adulterant, resulting in the sequestration of anionic species, usually present as counter ions to the active ingredient. Formation of noncovalent complexes between the cyclic host C4P compound and anionic guests is investigated using electrospray ionization–mass spectrometry (ESI–MS). Complexes with chloride, bromide, iodide, nitrate, and acetate are readily observed and mass spectrometry analysis provides identification via molecular weight characterization. Chloride and bromide complexes are also characterized by the isotopic distribution of their molecular ions. Formation of host–guest complexes is not observed for sulfate and phosphate salts, presumably due to steric hindrance and energetically unfavorable conditions.