Modified cobalt thiocyanate presumptive color test for ketamine hydrochloride

A new presumptive color test for ketamine hydrochloride is reported. The test is a modification of the cobalt thiocyanate test currently used for cocaine and involves basifying samples rather than acidifying them. The two-step procedure for liquids and three-step procedure for powdered samples are straightforward, definitive, and utilize reagents commonly used in forensic drug analysis. The test works on ketamine hydrochloride in both powder and liquid form and has a sensitivity of c. 1.25 mg. Performing the test with numerous other controlled substances and related chemicals demonstrates the test to be highly selective.     

微流控芯片技术在刑事科学中的应用

目的　阐述微流控芯片技术在法庭科学上的应用。方法　研究国内外已报道的微流控芯片快速、灵敏、高通量技术的有关资料。结果　提出在法医DNA检验、毒剂和毒物检测、麻醉剂或毒品检测、爆炸残留物检测等刑事技术上的应用前景。结论　从刑事侦查的角度看出该技术的巨大发展潜力     

Occurrence of contamination by controlled substances in Euro banknotes from the Spanish archipelago of the Canary Islands

The social problems of drug abuse are a matter of increasing global problem. Nowadays, international agencies need fresh methods to monitor trends of the use of illicit drugs. In this sense, small amounts of drugs are transferred to banknotes and they could be detected and quantified. An analytical procedure based upon extraction with organic solvent, liquid chromatography separation, and mass spectrometric detection allowed the identification of 21 drugs and metabolites in 120 used Euro banknotes collected in the Canary Islands (Spain). Most of the banknotes analyzed showed detectable drug residues (92.5%). Cocaine was the most frequently detected drug, present in approximately 90% of the samples. In addition, 75%, 35%, and 15% of the banknotes showed residues of amphetamine derivatives, opiates, and benzodiazepines, respectively. An average of three drug residues per banknote was detected. In summary, the presence of drug residues in banknotes could be useful as tracer for drugs prevalence.     

A Comparison of Chemical Enhancements for the Detection of Latent Blood,,

Luminol, Bluestar^®, and Hemascein^® were tested to compare detection sensitivities to latent blood. Untreated, EDTA‐treated human blood, and a catalytically similar blood substitute were diluted (neat to 1:1,000,000) and pipetted onto a variety of substrates. Luminol and Bluestar^® performed similarly on all surfaces and fabrics. Hemascein^® yielded poor results on wood surfaces, but performed well in the detection of latent blood on fabrics. Results from untreated, EDTA‐treated, and synthetic blood results indicate that EDTA‐treated blood is similar or slightly less sensitive than untreated blood at all dilutions and on all substrates, and the synthetic blood is less sensitive than real blood, but consistent in detection threshold and thus is useful as a training aid. Additionally, some foods and household chemicals that have previously been shown to cross‐react were tested with Bluestar^®, Hemascein^®, and luminol. Hemascein^® cross‐reacted with many substances, while both luminol reagents were more discriminating.     

Comparison of presumptive blood test kits including hexagon OBTI

Four presumptive blood tests, Hexagon OBTI, Hemastix(R), Leucomalachite green (LMG), and Kastle-Meyer (KM) were compared for their sensitivity in the identification of dried bloodstains. Stains of varying blood dilutions were subjected to each presumptive test and the results compared. The Hexagon OBTI buffer volume was also reduced to ascertain whether this increased the sensitivity of the kit. The study found that Hemastix(R) was the most sensitive test for trace blood detection. Only with the reduced buffer volume was the Hexagon OBTI kit as sensitive as the LMG and KM tests. However, the Hexagon OBTI kit has the advantage of being a primate specific blood detection kit. This study also investigated whether the OBTI buffer within the kit could be utilized for DNA profiling after presumptive testing. The results show that DNA profiles can be obtained from the Hexagon OBTI kit buffer directly.     

Evaluation of six presumptive tests for blood, their specificity, sensitivity, and effect on high molecular-weight DNA

Luminol, leuchomalachite green, phenolphthalein, Hemastix, Hemident, and Bluestar are all used as presumptive tests for blood. In this study, the tests were subjected to dilute blood (from 1:10,000 to 1:10,000,000), many common household substance, and chemicals. Samples were tested for DNA to determine whether the presumptive tests damaged or destroyed DNA. The DNA loci tested were D2S1338 and D19S433. Leuchomalachite green had a sensitivity of 1:10,000, while the remaining tests were able to detect blood to a dilution of 1:100,000. Substances tested include saliva, semen, potato, tomato, tomato sauce, tomato sauce with meat, red onion, red kidney bean, horseradish, 0.1 M ascorbic acid, 5% bleach, 10% cupric sulfate, 10% ferric sulfate, and 10% nickel chloride. Of all the substances tested, not one of the household items reacted with every test; however, the chemicals did. DNA was recovered and amplified from luminol, phenolphthalein, Hemastix, and Bluestar, but not from leuchomalachite green or Hemident.     

Comparison of modern techniques for saliva screening

Saliva stains present a unique challenge in the forensic setting, often challenging the analyst to weigh the value of presumptive indication of the fluid versus the potential for DNA analysis to yield identification information. There are many situations in which determining the presence of a body fluid is probative and further corroborates DNA evidence. That said, even a minute portion of sample consumed by a screening test could mean the difference between a full, partial, or null profile obtained through DNA analysis. The basis of presumptive testing or screening of saliva has historically been based on the presence of amylase, a component found in relatively high concentrations in human saliva versus other body fluids and substances. Though the current available methods for the screening of saliva in a forensic application have grown in number, the popularity of these methods seemingly has not. This study attempts to identify a specific and sensitive saliva screening test by comparing three modern techniques--the recently released SALIgAE, Phadebas, and starch-iodine mini-centrifuge test--on the basis of sensitivity, specificity, mixtures, and simulated casework samples while also considering sample consumption. The Phadebas method for presumptive saliva testing detected dilutions of neat saliva down to 1:200 versus considerably less sensitive results with SALIgAE and the starch-iodine mini-centrifuge test. Utilizing a screening test with a high degree of sensitivity, such as Phadebas, allows an analyst to gain a maximum amount of information in the form of body fluid indication and DNA results because of the consumption of a small portion of sample.     

A rapid test for heroin (3,6-diacetylmorphine) based on two chemiluminescence reactions

A rapid method for screening drug seizure samples for 3,6-diacetylmorphine (heroin), which consists of a simple hydrolysis procedure and flow-injection analysis with two chemiluminescence reagents, is described. Before hydrolysis, 3,6-diacetylmorphine evokes an intense response with a tris(2,2'-bipyridyl)ruthenium(III) reagent (prepared by dissolving the perchlorate salt in acetonitrile), and a relatively weak chemiluminescence response with a second reagent: potassium permanganate in an aqueous acidic polyphosphate solution. However, the permanganate reagent is extremely sensitive toward the hydrolysis products of 3,6-diacetylmorphine (i.e., 6-monoacetylmorphine and morphine). Some compounds commonly found in drug laboratories may cause false positives with tris(2,2'-bipyridyl)ruthenium(III), but do not produce the markedly increased response with the permanganate reagent after the hydrolysis procedure. The combination of these two tests therefore provides an effective presumptive test for the presence of 3,6-diacetylmorphine, which we have verified with 14 samples obtained from a forensic science laboratory.     

A simple microthermal desorption device

A new method for thermal desorption of small samples is presented. The method uses a solid phase microextraction (SPME) holder with the fiber removed. The sample-for example, an ink sample on paper-is simply placed inside the needle of the holder, where normally an SPME fiber is positioned. The thermal desorption is then performed on any kind of gas chromatograph in a manner similar to that for SPME analysis. The needle of the SPME holder penetrates the injector septum; the temperature of the thermal desorption is simply the temperature of the injector. No solvents or liquid nitrogen cooling are used. The paper sample is kept inside the holder needle during the analysis. After the analysis is completed, the sample is removed from the needle by pushing forward the steel wire inside the needle in the way normally used to perform sampling with the SPME fiber. The desorbed compounds were analyzed by gas chromatography with a flame ionization detector or by gas chromatography-mass spectrometry. The optimum temperature for desorption of ink samples on paper was 200 degrees C. The influence of the paper matrix is negligible at that temperature. Laboratories lacking the commercial device for thermal desorption can use this cheap device for the analysis of, for example, writing ink, printing ink, and inkjet ink samples on paper. Other types of samples can be investigated but the size of samples suitable for analysis is limited.     

Chemical composition and structure of the microcrystals formed between silver(I) and gamma-hydroxybutyric acid and gamma-hydroxyvaleric acid

This study examined microcrystals formed by silver with gamma-hydroxybutyric acid (GHB) and gamma-hydroxyvaleric acid (GHV), the five-carbon analog of GHB, in the presence of silver, copper, and lanthanide nitrates. Distinct microcrystals formed with silver (+1) and lanthanum (+3) ions but not with the copper (+2) ions. The crystals formed with GHB were distinctly different than those formed with GHV and in all cases, the drug microcrystals were easily distinguishable from reagent crystals. X-ray diffraction analysis provided definitive structure for the microcrystals. The morphological differences between the silver-GHB and silver-GHV crystals were characterized using simple measurements such as size and angles provided by image recognition software. The utility of the test for casework was demonstrated using spiked beverage samples.     

Identification of 1‐(2,3‐dihydro‐1H‐inden‐5‐yl)‐2‐(ethylamino)pentan‐1‐one (bk‐IVP) in a Seized Drug Exhibit

To circumvent the law by evading regulation and obscuring their identities in routine analyses, numerous substituted cathinones have entered the illicit drug market. These compounds have been coined “bath salts” by users. In the described case, the laboratory received an unknown white powder for controlled substances identification. The sample could not be immediately identified using standard methods and procedures. Ultimately, the structure was elucidated using GC‐MS, NMR, FTIR, GC‐SPIR, UV, and color tests to be 1‐(2,3‐dihydro‐1H‐inden‐5‐yl)‐2‐(ethylamino)pentan‐1‐one (bk‐IVP), a cathinone analog with a rarely observed nonoxygenated bicyclic ring system. Features of spectra and chemical tests are reported that distinguish this class of cathinones from heterocyclic analogs.     

从CTS能力验证计划看纤维物证检验的发展趋势

本文通过对2006年以来CTS法庭科学领域纤维测试项目结果的分析,总结了国内外纤维物证检验的技术方法,并对纤维物证检验的发展趋势进行了展望。     

Analysis of alprazolam by DART-TOF mass spectrometry in counterfeit and routine drug identification cases

The high prevalence of alprazolam abuse translates to an increased workload for crime laboratories in characterizing seized tablets. These tablets may originate as diverted pharmaceuticals or counterfeited mimics, so efficient analytical techniques should provide confirmatory data while minimizing destruction of evidence. We offer the first report of a validated forensic method for confirming alprazolam tablets by direct analysis in real time-time of flight (DART-TOF) mass spectrometric analysis. This technique provides rapid identification of target analytes with minimal sample preparation, allowing direct analysis in the atmospheric sample gap. Selectivity is achieved through high resolution and mass accuracy, unique ion fragments, and chlorine isotopic ratios. This method utilizes fragmentation in two separate voltage functions to observe the alprazolam pseudo molecular ion at 309.09070 using 40 V and major ion fragments of 281.07197 and 205.07657 at 120 V. These parameters allow our laboratory to confirm alprazolam tablets efficiently, without compromising quality forensic standards.     

Preliminary investigations into tris(2,2'-bipyridyl) ruthenium III as a chemiluminescent reagent for the detection of 3,6-diacetylmorphine (heroin) on surfaces

The use of tris(2,2'-bipyridyl) ruthenium (III) as a chemiluminescent spray reagent spot-test for heroin is discussed. Two forms of the reagent are investigated an aqueous and an anhydrous where both were found to give vastly different results. The aqueous reagent giving slow, low intensity chemiluminescence whilst the anhydrous reagent gave a fast, bright response in the presence of 3,6-diacetylmorphine. The anhydrous reagent is less sensitive the slow, intensity response is characteristic of only two opiates tested 3,6-diacetylmorphine and 3-monoacetylmorphine.     

Raman Spectroscopy as a Simple,Rapid, Nondestructive Screening Test for Methamphetamine in Clandestine Laboratory Liquids

Raman spectroscopy has found increased use in the forensic controlled substances laboratory in recent years due to its rapid and nondestructive analysis capabilities. Here, Raman spectroscopy as a screening test for methamphetamine in clandestine laboratory liquid samples is discussed as a way to improve the efficiency of a laboratory by identifying the most probative samples for further workup among multiple samples submitted for analysis. Solutions of methamphetamine in ethanol, diethyl ether, and Coleman fuel were prepared in concentrations ranging from 0.5% to 10% w/v, and Raman spectra of each were collected. A concentration‐dependant Raman peak was observed at 1003 per cm in each solution in 4% w/v and greater solutions. Case samples were analyzed and also found to reliably contain this diagnostic peak when methamphetamine was present. The use of this diagnostic indicator can save the forensic controlled substances laboratory time and materials when analyzing clandestine laboratory liquid submissions.     

Quick Screening of Crystal Methamphetamine/Methyl Sulfone Exhibits by Raman Spectroscopy

Abstract: The analysis of mixtures of “crystal meth” (usually comprised of methyl sulfone [MS] and methamphetamine [MA]) by gas chromatography‐mass spectrometry (GCMS) is routine in many forensic drug laboratories. The utilization of Raman spectroscopy for the identification of such mixtures quickly and without the need for a separation technique is discussed. Samples were dissolved in water and Raman spectra of the resulting aqueous solutions were collected. By comparing these spectra to spectra of methylsulfone and MA mixtures of known composition, an indication of the composition of the sample can be obtained in only a few minutes. This spectral comparison also can be used as a semi‐quantitative analysis of MA concentrations in such exhibits.     

Utilizing a magnetic locator to search for buried firearms and miscellaneous weapons at a controlled research site

Forensic personnel generally use basic all-metal detectors for weapon searches because of their ease of use and cost efficiency. For ferromagnetic targets, an alternative easy to use and low-cost geophysical tool is a magnetic locator. The following study was designed to demonstrate the effectiveness of a common, commercially available magnetic locator in forensic weapon searches by determining the maximum depth of detection for 32 metallic forensic targets and testing the effects of metallic composition on detection. Maximum depth of detection was determined for 16 decommissioned street-level firearms, six pieces of assorted scrap metals, and 10 blunt or bladed weapons by burying each target at 5-cm intervals until the weapons were no longer detected. As expected, only ferromagnetic items were detected; weapons containing both ferromagnetic and nonferromagnetic components were generally detected to shallower depths. Overall, the magnetic locator can be a useful addition to weapon searches involving buried ferromagnetic weapons.     

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.     

Comparative Analysis of the HV1 and HV2 Regions of Human Mitochondrial DNA by Denaturing High-Performance Liquid Chromatography

Abstract:  Denaturing high-performance liquid chromatography (DHPLC) was evaluated as a sequencing-independent means of detecting the presence of sequence differences in pair-wise mixtures of nonconcordant amplicons of human mitochondrial DNA (mtDNA). A total of 920 pair-wise combinations of HV1 and HV2 mtDNA amplicons from 95 individuals were assayed by DHPLC for sequence concordance/nonconcordance. For the 72 combinations of amplicons from different individuals who shared identical DNA sequences, DHPLC assays consistently indicated sequence concordance between the samples. This was in 100% agreement with sequencing data. For the 849 combinations of amplicons which differed in sequence, DHPLC detected the presence of sequence nonconcordance in all but 13 assays to yield 98.5% concordance with sequencing. Thus, DHPLC can be used to detect a diversity of sequence differences (transitions, transversions, insertions, and deletions) in the mtDNA D-loop. Accordingly, DHPLC may have utility as a presumptive indicator of mtDNA sequence concordance samples, as a screen for heteroplasmy/situational mixtures, and as a means for the physical fractionation of the individual contributors to an mtDNA mixture prior to sequencing.     

Estimating the Temperature of Heat‐exposed Bone via Machine Learning Analysis of SCI Color Values: A Pilot Study

Determining maximum heating temperatures of burnt bones is a long‐standing problem in forensic science and archaeology. In this pilot study, controlled experiments were used to heat 14 fleshed and defleshed pig vertebrae (wet bones) and archaeological human vertebrae (dry bones) to temperatures of 400, 600, 800, and 1000°C. Specular component included (SCI) color values were recorded from the bone surfaces with a Konica‐Minolta cm‐2600d spectrophotometer. These color values were regressed onto heating temperature, using both a traditional linear model and the k‐nearest neighbor (k‐NN) machine‐learning algorithm. Mean absolute errors (MAE) were computed for 1000 rounds of temperature prediction. With the k‐NN approach, the median MAE prediction errors were 41.6°C for the entire sample, and 20.9°C for the subsample of wet bones. These results indicate that spectrophotometric color measurements combined with machine learning methods can be a viable tool for estimating bone heating temperature.