Composite Machine Learning Algorithm for Material Sourcing,

This study developed a composite machine learning algorithm for attribution of materials of forensic interest (like ammonium nitrate) to original sources. k-nearest neighbor and random forest models were used for source elimination and classification, respectively, in a two-step, composite algorithm based on particle color, size/shape, and trace element concentration features. Novel approaches for simulation to supplement within-source reference features based on empirically measured multi-lot analyses, an improved hold-one-lot-out method for cross-validation, an assessment of the likelihood of the presence of a reference sample, fusion of the source probabilities from the respective classification models, and the calculation of metrics for assessing ensemble sourcing performance are described. Excellent sourcing predictions were obtained; the sourcing algorithm identified the correct source as the top choice 89% of the time, and the correct source was identified to be an average of 2.7 times more likely than the most likely incorrect source.     

Surviving the suicides of significant others: a case study

Psychological pain has been reported to be major contributing factor for completed suicide, and classical suicidology based its wisdom on this construct. In this paper we report the case of a patient whose family experienced a high number of suicides apparently due to an escalation of psychological pain in the family members after the successive suicides. We also briefly discuss the problem of helping survivors after the suicide of loved one.     

Visualization of dyes on thin-layer chromatography plates by means of the argon ion laser

A simple method for the detection of nanogram amounts of dyes by means of their fluorescence in the visible region of the spectrum is described. To stimulate the fluorescence, an argon ion laser with principal lines of 514.5 nm and 488.0 nm is used. The sensitivity of the technique allows the visualization of an amount of dye smaller than could be detected with either visible absorbance or ultraviolet stimulated fluorescence.     

Characterization and differentiation of cyclopropylfentanyl from E-crotonylfentanyl, Z-crotonylfentanyl,and 3-butenylfentanyl

Recently, a sample containing cyclopropylfentanyl was analyzed at this laboratory. Cyclopropylfentanyl began to appear in the United States' illicit drug markets in 2017. Unfortunately, cyclopropylfentanyl presents an analytical challenge due to its mass spectrum being almost identical to that of crotonylfentanyl. There are two possible isomers of crotonylfentanyl, Z- and E- crotonylfentanyl. In order to provide sufficient analytical data to distinguish the two isomers of crotonylfentanyl and cyclopropylfentanyl, crotonylfentanyl was synthesized and fully characterized. Each isomer was analyzed via nuclear magnetic resonance spectroscopy, gas chromatography–mass spectrometry, and Fourier transform infrared spectroscopy. During the synthesis of crotonylfentanyl, an unknown compound was formed. The identification of this compound and the analytical characterization of the two isomers of crotonylfentanyl are presented. Through the comparison of these compounds, it was confirmed that cyclopropylfentanyl can be differentiated from crotonylfentanyl.     

Profiling of illicit fentanyl using UHPLC-MS/MS

Methodology is presented for the profiling of fentanyl in seized drugs using ultra high performance liquid chromatography in combination with tandem mass spectrometry (UHPLC-MS/MS). Target analysis was performed for 40 fentanyl processing impurities, several of which are markers for a specific synthetic route (Siegfried or Janssen). For the separation of these solutes, an Acquity BEH C18 1.7 μm particle column (150 mm × 2.1 mm) with a binary 1% formic acid (pH 2.0)/acetonitrile gradient was used. For MS/MS detection, an atmospheric pressure positive electrospray source was employed with selected reaction monitoring (SRM). The coupling of the high separation power of UHPLC with the highly selective and sensitive detection of MS/MS is amenable to the determination of synthetic route and linking of drug seizures. The technology is also applicable to exhibits containing trace levels of fentanyl in the presence of significantly excess amounts of heroin and/or adulterants.     

An aqueous-organic extraction method for the isolation and identification of psilocin from hallucinogenic mushrooms

A simple aqueous extraction method for the isolation and identification of psilocin from Psilocybe cubensis mushrooms is reported. This method employs a dephosphorylation of the phosphate ester to psilocin, which facilitates a greater product yield and simplifies identification. Psilocin extracted by this method is sufficiently concentrated and free of cocontaminants to allow identification by infrared spectroscopy and gas chromatography/mass spectrometry.     

Four new illicit cocaine impurities from the oxidation of crude cocaine base: formation and characterization of the diastereomeric 2,3-dihydroxy-3-phenylpropionylecgonine methyl esters from cis- and trans-cinnamoylcocaine

Four new impurities have recently been detected in the gas chromatographic signature profiles of many illicit cocaine hydrochloride exhibits. These impurities are only seen in exhibits that have been oxidized and are most prominent in samples that have been highly oxidized. Exhibits containing these compounds were subjected to gas and liquid chromatographic-mass spectrometric analyses to determine the identity of the impurities. These impurities were subsequently synthesized to verify their structures. Four diastereomeric diols formed from the oxidation of cis- and trans-cinnamoylcocaine were characterized by nuclear magnetic resonance spectrometry, mass spectrometry, and synthesis. Oxidation of cis-cinnamoylcocaine in neutral conditions yielded (2R,3R)-dihydroxy-3-phenylpropionylecgonine methyl ester and (2S,3S)-dihydroxy-3-phenylpropionylecgonine methyl ester, while trans-cinnamoylcocaine produced (2R,3S)-dihydroxy-3-phenylpropionylecgonine methyl ester and (2S,3R)-dihydroxy-3-phenylpropionylecgonine methyl ester. The recent appearance of these new impurities suggests that some illicit cocaine processors have modified their oxidation procedures of crude cocaine base for transformation into illicit refined cocaine hydrochloride.     

Apparent effects of glyphosate on alkaloid production in coca plants grown in Colombia

During the routine analysis of coca leaf material from South America, alkaloids in Erythroxylum coca var. ipadu (ECVI) leaf samples from fields suspected of being treated with glyphosate were compared with those from non-treated E. coca var. ipadu and Erythroxylum novogranatense var. novogranatense (ENVN) plants. Cocaine levels in leaf tissue from non-treated ECVI and ENVN were 0.53+/-0.08% and 0.64+/-0.08% (w/w), respectively, whereas leaves from treated plants were nearly devoid of cocaine. Further analysis demonstrated the presence of several previously undescribed N-nortropane alkaloids, several of which were tentatively identified. The results suggest that applications of glyphosate to coca plants can have dramatic effects on the quantity and quality of alkaloids produced by surviving or subsequent leaves. The analytical data presented will be of value to forensic chemists who encounter illicit cocaine preparations containing alkaloids produced from coca plants treated with glyphosate.     

Stampede to judgement: persuasive influence and herding behavior by courts

We model appeals courts as Bayesian decision makers with privateinformation about a supreme court's interpretation of the law;each court also observes the previous decisions of other appealscourts in similar cases. Such 'persuasive influence' can cause'herding' behavior by later appeals courts as decisions progressivelyrely more on previous decisions and less on a court's privateinformation. We provide an example drawn from a recent UnitedStates Supreme Court decision finding unconstitutional a basicprovision of a law previously found constitutional by six circuitcourts. Herding on the wrong decision may remain uncorrected,since review of harmonious decisions is rare.