David Morello - Academia.edu (original) (raw)

Papers by David Morello

Drug Testing and Analysis, Dec 12, 2021

The forensic analysis of stable isotopes is a valuable tool to geo-source natural or semi-synthet... more The forensic analysis of stable isotopes is a valuable tool to geo-source natural or semi-synthetic drugs such as cocaine and heroin. The present study describes a novel methodology to isolate morphine from opium for isotopic analysis. Furthermore, this isotopic data from regional sources is corroborated with morphine data obtained from seized heroin (de-acetylated to morphine) from the same regions. All five primary alkaloids of opium, namely morphine, codeine, thebaine, noscapine and papaverine, were quantified using high performance liquid chromatography with PDA before the preparative experiment to gather a complete major alkaloidal profile. Morphine fractions of authentic opium submissions from Mexico, South America, Southwest Asia, and Southeast Asia were isolated and collected using preparative high performance liquid chromatography, and the collected morphine samples were subsequently analyzed by isotope ratio mass spectrometry. Carbon and nitrogen isotope data are presented. The data demonstrates that nitrogen ratios are capable of differentiating samples from Mexico and South America while carbon ratios are able to distinguish Southwest Asian samples from other source regions. Analogous results have routinely been observed (as part of Heroin Signature Program analysis) for morphine obtained from de-acetylated authentic heroin samples from the same source regions. The results suggest that the poppy growing region has a greater influence on the carbon and nitrogen isotope values than the heroin manufacturing processes employed. When utilized in conjunction with existing signature methodologies, carbon and nitrogen isotope ratio data can enhance the ability to geo-source heroin.

Scientific Reports, Mar 23, 2016

Previously, geo-sourcing to five major coca growing regions within South America was accomplished... more Previously, geo-sourcing to five major coca growing regions within South America was accomplished. However, the expansion of coca cultivation throughout South America made sub-regional origin determinations increasingly difficult. The former methodology was recently enhanced with additional stable isotope analyses (2 H and 18 O) to fully characterize cocaine due to the varying environmental conditions in which the coca was grown. An improved data analysis method was implemented with the combination of machine learning and multivariate statistical analysis methods to provide further partitioning between growing regions. Here, we show how the combination of trace cocaine alkaloids, stable isotopes, and multivariate statistical analyses can be used to classify illicit cocaine as originating from one of 19 growing regions within South America. The data obtained through this approach can be used to describe current coca cultivation and production trends, highlight trafficking routes, as well as identify new coca growing regions. Cocaine remains one of the most widely used narcotics in the world, and the United States is a primary consumer 1. The widespread abuse of cocaine has led to numerous investigations into its production and characterization 2-6. In the past, profiling studies have focused on the isolation of trace alkaloids present in illicit cocaine with the intent of comparing and thus linking samples seized by law enforcement agencies 7-10. Comparison analyses provide valuable information; however, due to the movement of cocaine for processing and distribution between multiple locations, successful sample-to-sample association is often difficult. Chemical profiling does, however, have significant merit in building the foundation for determining the origin of illicit cocaine. Geographically sourcing cocaine not only addresses the complex movement of cocaine but may also influence law enforcement's coca eradication and cocaine interdiction strategies. Cocaine origin determinations were first successfully accomplished through the utilization of trace alkaloid data in combination with stable isotope ratios (δ) of purified cocaine 11. Five coca growing regions throughout South America were investigated: The Chapare Valley in Bolivia, the Huallaga/Ucayali and Apurimac Valleys in Peru, and the Guaviare and Putumayo-Caquetá regions in Colombia. Five variables were considered: tropacocaine, trimethoxycocaine, total truxilline content, and two stable isotope ratios, δ 13 C and δ 15 N. The alkaloid content of cocaine is primarily indicative of the coca variety utilized for production, as the minor plant alkaloids that are carried through illicit processing vary by cultivar. Additionally, the prevalence of each variety differs throughout South America, thus indicating a probable region of growth 3-5. Recent analyses of coca varieties and numerous cultigens have further enhanced our understanding of the known variations of alkaloid content within cocaine 12. Stable isotope ratios are utilized in various fields of study for geographical origin determinations and predicting environmental patterns 13-15. The stable isotopes present in cocaine are unaffected by illicit processing methods 16 and are therefore a reflection of the environment in which the coca was cultivated. Due to the natural variations in alkaloids and stable isotopes, characteristic profiles were easily identified and thus provided the basis for classification of cocaine by country of origin, i.e.,

Forensic Science International, 2014

Differentiating methamphetamine samples produced from ephedrine and pseudoephedrine from phenyl-2... more Differentiating methamphetamine samples produced from ephedrine and pseudoephedrine from phenyl-2-propanone precursors is critical for assigning synthetic route information for methamphetamine profiling. The use of isotope ratio mass spectrometry data is now a key component for tracking precursor information. Recent carbon (δ(13)C) isotope results from the analysis of numerous methamphetamine samples show clear differentiation for ephedrine and pseudoephedrine-produced samples compared to P2P-produced samples. The carbon isotope differences were confirmed from synthetic route precursor studies.

Journal of Forensic Sciences, Mar 1, 2006

Laudanosine, reticuline, codamine, and laudanine are members of the tetrahydrobenzylisoquinoline ... more Laudanosine, reticuline, codamine, and laudanine are members of the tetrahydrobenzylisoquinoline family of natural products. These alkaloids are present in the opium poppy, Papaver somniferum, and are subsequently found as impurities in clandestinely processed morphine. Morphine is then synthesized to heroin using hot acetic anhydride. During the course of this study, it was determined that these four tetrahydrobenzylisoquinolines undergo degradation to a series of 18 neutral impurities when subjected to hot acetic anhydride. Based on the degradation pathway, these new impurities were categorized into two sets of impurities called the C1-acetates compounds and the stilbene compounds. Synthesis, isolation, and structural elucidation information is provided for the tetrahydrobenzylisoquinoline alkaloids, and the new neutral impurities have been studied. Several hundred authentic heroin samples were analyzed using an established heroin signature program method. This methodology features the detection of trace neutral impurities present in heroin samples. It was determined that all 18 new impurities were detected in various quantities in four different types of heroin samples. Analytical results featuring these new impurities are reported for South American-, Southwest Asian-, Mexican-, and Southeast Asian-type heroin samples. These new impurities, coupled with other established forensic markers, enhance the ability to classify illicit heroin samples.

Journal of Forensic Sciences, Nov 1, 1995

Methodology has been developed which utilizes static headspace-gas chromatography-mass spectromet... more Methodology has been developed which utilizes static headspace-gas chromatography-mass spectrometry (SHS-GC-MS) to identify and quantitate residual solvents occluded in illicit cocaine HCl and heroin HCl. The liberation of the occluded solvents was ensured by complete solubilization of the crystal matrices in aqueous 22% sodium sulfate. Ion trap mass spectrometry is used for both identification and quantitation; five deuterated, structurally related internal standards are utilized for more accurate quantitation. Overall method precision for 25 commonly encountered solvents averaged 6.7% RSD. Minimum detection limits ranged from 3 to 87 ppm for a 15 mg equivalent cocaine sample weight, and from 2 to 43 ppm for a 30 mg equivalent heroin sample weight. Qualitative and quantitative data for the 25 most commonly encountered occluded solvents in cocaine HCl and heroin HCl exhibits are presented.

Science & Justice, Mar 1, 2018

For nearly 30 years, the methods utilized in illicit cocaine hydrochloride production have remain... more For nearly 30 years, the methods utilized in illicit cocaine hydrochloride production have remained relatively consistent. Cocaine hydrochloride is typically produced one kilogram at a time. As a result, each individual kilogram is unique and distinct from other kilograms in any particular seizure based on the total alkaloid profile, occluded solvent profile, and isotopic signature. Additionally, multi-kilogram cocaine seizures are often comprised of cocaine from several different coca growing regions. There has been a documented shift in this type of processing based on the recent analysis of a large cocaine seizure in the Eastern Pacific. Signature analyses of samples from 21 kg randomly selected from a 517 kg seizure were virtually identical. Triplicate analyses of each sample via gas chromatography with flame ionization detection, static headspace gas chromatography mass spectrometry, and isotope ratio mass spectrometry were completed. An initial outlier evaluation of the data and an in-depth univariate analysis indicated there was no statistically significant difference among the 21 samples at the 95% confidence interval. Principal components analysis did reveal consistent minor deviations between the samples and known authentic data from the Nariño coca growing region of Colombia. These deviations were only observed on the latter principal components and could be explained by differences in solvent selection during cocaine hydrochloride processing. Chemical analyses in addition to a thorough statistical evaluation suggest a shift in the traditional small-batch method of cocaine processing to a multi-kilogram, high throughput approach.

Drug Testing and Analysis, Nov 27, 2021

Drug Enforcement Administration's (DEA) Cocaine Signature Program previously identified 19 co... more Drug Enforcement Administration's (DEA) Cocaine Signature Program previously identified 19 coca‐growing regions within South America and developed methodology to geo‐source cocaine using a combination of trace cocaine alkaloids, stable isotopes, and multivariate statistics. Twenty‐nine coca leaf samples collected in 2016 and 2019 from a previously unanalyzed coca‐growing region located in Puno, Peru, were analyzed with this methodology. Trace cocaine alkaloids and stable isotopes were compared with other Peruvian regions. Minor differences were observed in the extracted cocaine alkaloid profiles when compared with samples collected from the Ucayali‐Huallaga Valley and Cusco‐Apurimac regions while the stable isotopes of δ2H (−177.1‰) and δ18O (23.8‰) were enriched. Puno's alkaloid and stable isotope results are presented in this publication to assist forensic laboratories and enhance their cocaine geo‐sourcing capabilities.

Journal of Forensic Sciences, Sep 1, 2000

The current clandestine methodology for the manufacture of illicit cocaine hydrochloride utilizes... more The current clandestine methodology for the manufacture of illicit cocaine hydrochloride utilizes microwave heating in order to dry the finished product. This study addresses the effects this step has on the occluded solvents present in newly prepared cocaine hydrochloride. Nine 1-kilogram-sized batches of cocaine hydrochloride were prepared from cocaine base using a variety of solvents or solvent mixtures commonly utilized in clandestine laboratories, pressed into bricks, and submitted to microwave heating. Residual solvents were qualitatively and quantitatively monitored before, during, and following the microwaving step by static headspace-gas chromatography-mass spectrometry. All solvents used in the conversion process were easily detected in the bricks even after extensive irradiation, confirming that occluded solvents are extremely resistant to removal by microwave heating. Qualitative and quantitative data corresponding to the residual solvents in the prepared cocaine hydrochloride bricks are presented.

$Research paper thumbnail of The isotopic fractionation of carbon, nitrogen, hydrogen, and oxygen during illicit production of cocaine base in South America$

Forensic Science International, 2017

Highlights-Fractionation of four stable isotopes in cocaine was investigated.-An observable fract... more Highlights-Fractionation of four stable isotopes in cocaine was investigated.-An observable fractionation event occurred during precipitation of cocaine base.-All four stable isotopes exhibit a fractionation opposite of the classic Rayleigh.-Nitrogen and hydrogen are most affected during the observed fractionation event.

Journal of Forensic Sciences, 1995

Drug Testing and Analysis, 2021

DEA's Cocaine Signature Program previously identified 19 coca-growing regions within South Am... more DEA's Cocaine Signature Program previously identified 19 coca-growing regions within South America and developed methodology to geo-source cocaine using a combination of trace cocaine alkaloids, stable isotopes, and multivariate statistics. Twenty-nine coca leaf samples collected in 2016 and 2019 from a previously unanalyzed coca-growing region located in Puno, Peru were analyzed with this methodology. Trace cocaine alkaloids and stable isotopes were compared to other Peruvian regions. Minor differences were observed in the extracted cocaine alkaloid profiles when compared to samples collected from the Ucayali-Huallaga Valley and Cusco-Apurimac regions while the stable isotopes of δ2 H (-177.1‰) and δ18 O (23.8‰) were enriched. Puno's alkaloid and stable isotope results are presented in this publication to assist forensic laboratories and enhance their cocaine geo-sourcing capabilities.

Science & Justice, 2018

For nearly 30years, the methods utilized in illicit cocaine hydrochloride production have remaine... more For nearly 30years, the methods utilized in illicit cocaine hydrochloride production have remained relatively consistent. Cocaine hydrochloride is typically produced one kilogram at a time. As a result, each individual kilogram is unique and distinct from other kilograms in any particular seizure based on the total alkaloid profile, occluded solvent profile, and isotopic signature. Additionally, multi-kilogram cocaine seizures are often comprised of cocaine from several different coca growing regions. There has been a documented shift in this type of processing based on the recent analysis of a large cocaine seizure in the Eastern Pacific. Signature analyses of samples from 21kg randomly selected from a 517kg seizure were virtually identical. Triplicate analyses of each sample via gas chromatography with flame ionization detection, static headspace gas chromatography mass spectrometry, and isotope ratio mass spectrometry were completed. An initial outlier evaluation of the data and an in-depth univariate analysis indicated there was no statistically significant difference among the 21 samples at the 95% confidence interval. Principal components analysis did reveal consistent minor deviations between the samples and known authentic data from the Nariño coca growing region of Colombia. These deviations were only observed on the latter principal components and could be explained by differences in solvent selection during cocaine hydrochloride processing. Chemical analyses in addition to a thorough statistical evaluation suggest a shift in the traditional small-batch method of cocaine processing to a multi-kilogram, high throughput approach.

Journal of Forensic Sciences, 1995

A method to determine trehalose in yeast extract using paper chromatography was investigated in t... more A method to determine trehalose in yeast extract using paper chromatography was investigated in this manuscript.Meanwhile,a process to determine the concentration of trehalose by Anthrone-sulphuric acid colorimetric method was developed.Compared to the results from HPLC,the paper chromatography method was identified as highly accurate and precise in the determination of trehalose.Therefore,the paper chromatography methods was proven to be easy operate and suitable for the screening of strains producing trehalose.

$Research paper thumbnail of The isotopic fractionation of carbon, nitrogen, hydrogen, and oxygen during illicit production of cocaine base in South America$

Forensic science international, 2017

Stable isotope measurements have become a key component in sourcing the origin of illicit cocaine... more Stable isotope measurements have become a key component in sourcing the origin of illicit cocaine seized within the United States. Therefore, it is imperative to understand the process by which isotopes may be fractionated during illicit cocaine processing. In a controlled observational study, there was apparent isotopic fractionation of carbon, nitrogen, hydrogen, and oxygen. To investigate the potential source of the fractionation, cocaine base was fractionally precipitated from a dilute sulfuric acid solution with dilute ammonium hydroxide. The values of δ(13)C, δ(15)N, δ(2)H, and δ(18)O for each fraction were measured by isotope ratio mass spectrometry (IRMS). There was an equilibrium fractionation observed in all measured stable isotopes. Early fractions were depleted, and later fractions were enriched, with (15)N and (2)H being the most affected. The described trend is opposite of the Rayleigh distillation observed for cocaine hydrochloride precipitation.