Development and Validation of a Novel and Fast Detection Method for Cannabis sativa: A 19-Plex Short Tandem Repeat Typing System

In recent years, influenced by the legalization of Cannabis sativa in some countries and regions, the number of people who smoke or abuse C. sativa has continuously grown, cases of transnational C. sativa trafficking have also been increasing. Therefore, fast and accurate identification and source tracking of C. sativa have become urgent social needs. In this study, we developed a new 19-plex short tandem repeats (STRs) typing system for C. sativa, which includes 15 autosomal STRs (D02-CANN1, C11-CANN1, 4910, B01-CANN1, E07-CANN1, 9269, B05-CANN1, H06-CANN2, 5159, nH09, CS1, ANUCS 305, 3735, and ANUCS 302 and 9043), two X-chromosome STRs (ANUCS 501 and 1528), one sex-determining marker (DM016, on Y-chromosome), and a quality control marker (DM029, on autosome). The whole polymerase chain reaction (PCR) process could finish within 1 h, making the system suitable for fast detection. The PCR products were detected and separated with an Applied Biosystems 3500XL Genetic Analyser. Developmental validation studies indicated that the 19-plex typing system was accurate, reliable and sensitive, which could also deconvolute mixed C. sativa samples. Specifically, the sensitivity study showed that a full genotyping profile was obtainable with as low as 125 pg of C. sativa DNA. The species specificity study demonstrated that this multiplex has no cross-reactivity with common non C. sativa DNA. In the population study, a total of 162 alleles at 15 autosomal STRs and 14 alleles at two X-chromosome STRs were detected among 85 samples. The efficiency parameters, including the total discrimination power (TDP) and the combined power of exclusion (CPE) of the system, were calculated to exceed 0.999 999 999 999 988 and 0.998 455 889 684 078, respectively, further proving that the system could meet the needs of individual identification. To the extent of the known studies, this is the first study that included the C. sativa sex-determining marker. In conclusion, the developed new 19-plex STR typing system can successfully achieve the purposes of species identification, gender determination, and individual identification, which could be a powerful tool in tracing trade routes of particular drug syndicates or dealers or in linking certain C. sativa to a crime scene.

A novel set of short microhaplotypes based on non-binary SNPs for forensic challenging samples

Short tandem repeats (STRs) are the most widely used genetic markers in forensic application, but they are not ideal genetic markers for the analysis of forensic challenging samples such as highly degraded or unbalanced mixed samples because of their relatively large amplicons and stutter peaks. In this study, we developed a set of short microhaplotypes based on non-binary SNPs with molecular extent sizes no longer than 60 bases and genotyped 100 unrelated individuals from northern Han groups. Our results showed this panel has similar discrimination power to STR kits, as the combined random match probability (CMP) reached 1.396 × 10^-22 and mean effective number of alleles (Ae) was 3.59. The cumulative probability of exclusion for duos (CPE-duos) was 0.999919 and the cumulative probability of exclusion for trios (CPE-trios) was 0.9999999987, suggesting this panel could be applied for forensic personal identification and parentage testing independently. Population differentiation in 26 populations from the 1000 Genomes Project indicated this panel could distinguish populations from Africa, East Asia, South Asia, America, and Europe. These microhaplotypes based on non-binary SNPs have short amplicons, good discrimination power, no stutter artifacts, and have great potential in detection of highly degraded and unbalanced mixtures for personal identification, paternity testing, and ancestry inference.

Developmental validation of the STRscan-17LC kit: a 6 Dye STR kit enhanced stability and ability to detect degraded samples

Genotyping of short tandem repeat (STR) markers is the basic method of forensic science. Enhanced technologies are needed to meet the requirements of databasing and casework samples. The STRscan-17LC kit is a 6 Dye STR kit which amplifies 16 STR loci: D3S1358, TPOX, D16S539, vWA, D2S1338, CSF1PO, D19S433, D7S820, FGA, D8S1179, D5S818, D13S317, D18S51, TH01, D12S391, and D21S11 and the sex-determinant locus amelogenin. This kit is designed for better tolerance to PCR inhibitors and analysis of mildly degraded samples with all fragments smaller than 330 bases. In this study, the STRscan-17LC kit is validated according to the SWGDAM (Scientific Working Group on DNA Analysis Methods) guidelines, including PCR-based studies, sensitivity, precision and accuracy, inhibitors, species specificity, DNA mixture studies, population, and concordance studies. The validation results suggest that the STRscan-17LC kit is a useful tool for forensic application.

Inorganic oxidizer detection from propellants, pyrotechnics, and homemade explosive powders using gradient elution moving boundary electrophoresis

Advancement in rapid targeted chemical analysis of homemade and improvised explosive devices is critical for the identification of explosives-based hazards and threats. Gradient elution moving boundary electrophoresis (GEMBE), a robust electrokinetic separation technique, was employed for the separation and detection of common inorganic oxidizers from frequently encountered fuel-oxidizer mixtures. The GEMBE system incorporated sample and run buffer reservoirs, a short capillary (5 cm), an applied electric field, and a pressure-driven counterflow. GEMBE provided a separation format that allowed for continuous injection of sample, selectivity of analytes, and no sample cleanup or filtration prior to analysis. Nitrate, chlorate, and perchlorate oxidizers were successfully detected from low explosive propellants (e.g., black powders and black powder substitutes), pyrotechnics (e.g., flash powder), and tertiary explosive mixtures (e.g., ammonium nitrate- and potassium chlorate-based fuel-oxidizer mixtures). Separation of these mixtures exhibited detection without interference from a plethora of additional organic and inorganic fuels, enabled single particle analysis, and demonstrated semiquantitative capabilities. The bulk counterflow successfully excluded difficult components from fouling the capillary, yielding estimated limits of detection down to approximately 10 μmol/L. Finally, nitrate was separated and detected from postblast debris collected and directly analyzed from two nitrate-based charges.

Separation and Detection of Trace Fentanyl from Complex Mixtures Using Gradient Elution Moving Boundary Electrophoresis

The current opioid epidemic remains an ongoing challenge, exacerbated by the extreme potency of synthetic opioids (e.g., fentanyl and fentanyl analogues), leading to an increase in adulterated heroin-related deaths. The increasing prevalence of fentanyl and fentanyl analogues in mixtures with heroin and other adulterants, excipients, and bulking agents has placed an emphasis on trace analysis methods for their detection from complex drug mixtures. Here, gradient elution moving boundary electrophoresis (GEMBE), a robust and miniaturized electrophoretic separation technique, was employed for the separation and detection of fentanyl and nine (9) fentanyl analogues from mixtures. GEMBE incorporated a short capillary (5 cm × 15 μm i.d.) for the electrophoretic separation of analytes with an opposing bulk counterflow. As the velocity of the counterflow was varied, analytes with differing electrophoretic mobilities entered the separation channel at different times and were analyzed as moving boundaries by contactless conductivity detection. The continuous injection of sample, driven by a controlled and variable pressure, both provided selectivity of the analytes and prevented contaminants or particulate within the sample from entering the separation capillary. Fentanyl was successfully separated and detected down to 2.5 μmol/L and demonstrated only 50% to 60% signal suppression in dilute binary mixtures with heroin and other common adulterants and excipients at 30:1 (compound/fentanyl) concentration ratios. In addition, GEMBE was successfully applied to a few adjudicated case samples of fentanyl-related mixtures exhibiting dyes and visible particulate. The short capillaries, contactless detection format utilized here, and continuous injection of sample allow for a small footprint platform that is easy-to-use for forensic analyses.

Developmental validation of a 6-dye typing system with 27 loci and application in Han population of China

In this study, a novel 27-locus system (now known as the SureID PanGlobal system), including 24 autosomal STRs (D3S1358, TH01, D21S11, D18S51, Penta E, D12S391, D6S1043, D2S1338, D1S1656, D2S441, D5S818, D13S317, D7S820, D19S433, CSF1PO, Penta D, vWA, D8S1179, TPOX, FGA, D16S539, D22S1045, SE33, D10S1248), two Y-chromosome markers (DYS391 and Y-indel) and the sex determining marker, Amelogenin was developed with six fluorescent dyes labeling. The included STR loci belonged to the core loci in the Combined DNA Index System (CODIS) and the European Standard Set (ESS) as well as some additional loci commonly used in commercial kits and national DNA databases. This paper describes the validation studies conducted with the SureID PanGlobal system using Applied Biosystems 3500 XL Genetic Analyzer for fragment length detection that included the analysis of the following parameters and aspects: PCR conditions, sensitivity, species specificity, inhibition, precision, stutter, DNA mixtures, and stability studies with crime scene samples. The studies demonstrated that the SureID PanGlobal system is reproducible, accurate, sensitive and robust for forensic application and databasing. Additionally, the whole cycling time of the system can finish within 65 minutes, which was developed specifically for rapid and reliable generation of DNA profiles obtained from blood, buccal swabs and forensic stains.

Screening determination of four amphetamine-type drugs in street-grade illegal tablets and urine samples by portable capillary electrophoresis with contactless conductivity detection

A simple and inexpensive method for the identification of four substituted amphetamines, namely, 3,4-methylenedioxy methamphetamine (MDMA), methamphetamine (MA), 3,4-methylenedioxy amphetamine (MDA) and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) was developed using an in-house constructed semi-automated portable capillary electrophoresis instrument (CE) with capacitively coupled contactless conductivity detection (C(4)D). Arginine 10mM adjusted to pH4.5 with acetic acid was found to be the optimal background electrolyte for the CE-C(4)D determination of these compounds. The best detection limits achieved with and without a sample preconcentration process were 10ppb and 500ppb, respectively. Substituted amphetamines were found in different seized illicit club drug tablets and urine samples collected from different suspected users. Good agreement between results from CE-C(4)D and those with the confirmation method (GC-MS) was achieved, with correlation coefficients for the two pairs of data of more than 0.99.

Ultrasensitive analysis of lysergic acid diethylamide and its C-8 isomer in hair by capillary zone electrophoresis in combination with a stacking technique and laser induced fluorescence detection

This article deals with the development and validation of a novel capillary zone electrophoresis (CZE) with laser induced fluorescence detection method for the analysis of lysergic acid diethylamide (LSD) and its isomer iso-LSD in hair samples. The separation of both analytes has been achieved in less than 13 min in a 72-cm effective length capillary with 75-μm internal diameter. As running buffer 25 mM citrate, pH 6.0 has been employed and separation temperature and voltage of 20 °C and 13 kV respectively, were applied. Field amplified sample injection (FASI) has been employed for on-line sample preconcentration, using ultrapure water containing 117 μM H3PO4 as optimum injection medium. Injection voltage and time have been optimized by means of experimental design, obtaining values of 7 kV and 15s, respectively. Methylergonovine has been employed as internal standard in order to compensate irreproducibility from electrokinetic injection. The analytical method has been applied to hair samples, previous extraction of the target analytes by ultrasound assisted solid-liquid extraction at 40 °C for 2.5 h, employing acetonitrile as extracting solvent. Linear responses were found for LSD and iso-LSD in matrix-matched calibrations from around 0.400 up to 50.0 pg mg(-1). LODs (3 S/N) in the order of 0.100 pg mg(-1) were calculated for both analytes, obtaining satisfactory recovery percentages for this kind of sample.

Electromigrative separation techniques in forensic science: combining selectivity, sensitivity, and robustness

In this review we introduce the advantages and limitations of electromigrative separation techniques in forensic toxicology. We thus present a summary of illustrative studies and our own experience in the field together with established methods from the German Federal Criminal Police Office rather than a complete survey. We focus on the analytical aspects of analytes' physicochemical characteristics (e.g. polarity, stereoisomers) and analytical challenges including matrix tolerance, separation from compounds present in large excess, sample volumes, and orthogonality. For these aspects we want to reveal the specific advantages over more traditional methods. Both detailed studies and profiling and screening studies are taken into account. Care was taken to nearly exclusively document well-validated methods outstanding for the analytical challenge discussed. Special attention was paid to aspects exclusive to electromigrative separation techniques, including the use of the mobility axis, the potential for on-site instrumentation, and the capillary format for immunoassays. The review concludes with an introductory guide to method development for different separation modes, presenting typical buffer systems as starting points for different analyte classes. The objective of this review is to provide an orientation for users in separation science considering using capillary electrophoresis in their laboratory in the future.

Analysis of questioned documents: a review

During the last years (2000-2014), many publications concerning the forensic analysis of questioned documents have been published, and new techniques and methodologies are nowadays employed to overcome forensic caseworks. This article reviews a comprehensive collection of the works focused on this issue, including dating studies, the analysis of inks from pens and printers, the analysis of paper, the analysis of other samples related to questioned documents and studies on intersecting lines. These sections highlight the most relevant analytical studies by a wide range of analytical techniques. Separation and spectrometric techniques are critically discussed and compared, emphasizing the advantages and disadvantages of each one. Finally, concluding remarks on the research published are included.

I-DNASE21 system: development and SWGDAM validation of a new STR 21-plex reaction

I-DNASE21 is a new STR multiplex system that amplifies 21 STR autosomal loci, plus the amelogenin locus in one reaction. This system has been designed to analyze all the STR loci included in the Combined DNA Index System (CODIS), Interpol Standard Set of Loci (ISSL), Extended European Standard Set (ESS-Extended), UK National Criminal Intelligence DNA Database (NDNAD) and German Core loci (GCL). This manuscript presents the validation of the I-DNASE21 system according to the revised guidelines issued by the Scientific Working Group on DNA Analysis Methods (SWGDAM). The results of this validation, added to the extremely high discriminatory power showed, suggest that I-DNASE21 could be a potentially helpful tool for identification and kinship determination even in complex paternity cases.

Capillary electrophoretic and extraction conditions for the analysis of Catha edulis FORKS active principles

A capillary electrophoretic method, which allowed the detection and separation of the active principles of Catha edulis, i.e. cathinone, cathine and phenylpropanolamine, was developed. A suitable internal standard (nicotinamide), which permitted the quantification of the analytes reducing the variability of the migration times due to EOF changes, was identified. The analytical method was validated, assessing linearity, sensitivity and repeatability, showing optimal features for the analysis of the vegetable material. Moreover extraction conditions were investigated to achieve the exhaustion of the plant material in the fastest and most efficient way to meet the requirements of the Court.

Dispersive liquid-liquid microextraction prior to field-amplified sample injection for the sensitive analysis of 3,4-methylenedioxymethamphetamine, phencyclidine and lysergic acid diethylamide by capillary electrophoresis in human urine

A novel capillary zone electrophoresis (CZE) with ultraviolet detection method has been developed and validated for the analysis of 3,4-methylenedioxymethamphetamine (MDMA), lysergic acid diethylamide (LSD) and phencyclidine (PCP) in human urine. The separation of these three analytes has been achieved in less than 8 min in a 72-cm effective length capillary with 50-μm internal diameter. 100 mM NaH(2)PO(4)/Na(2)HPO(4), pH 6.0 has been employed as running buffer, and the separation has been carried out at temperature and voltage of 20°C, and 25kV, respectively. The three drugs have been detected at 205 nm. Field amplified sample injection (FASI) has been employed for on-line sample preconcentration. FASI basically consists in a mismatch between the electric conductivity of the sample and that of the running buffer and it is achieved by electrokinetically injecting the sample diluted in a solvent of lower conductivity than that of the carrier electrolyte. Ultrapure water resulted to be the better sample solvent to reach the greatest enhancement factor. Injection voltage and time have been optimized to 5 kV and 20s, respectively. The irreproducibility associated to electrokinetic injection has been correcting by using tetracaine as internal standard. Dispersive liquid-liquid microextraction (DLLME) has been employed as sample treatment using experimental design and response surface methodology for the optimization of critical variables. Linear responses were found for MDMA, PCP and LSD in presence of urine matrix between 10.0 and 100 ng/mL approximately, and LODs of 1.00, 4.50, and 4.40 ng/mL were calculated for MDMA, PCP and LSD, respectively. The method has been successfully applied to the analysis of the three drugs of interest in human urine with satisfactory recovery percentages.

Analysis of drugs of forensic interest with capillary zone electrophoresis/time-of-flight mass spectrometry based on the use of non-volatile buffers

The present work is aimed at investigating the influence of the background electrolyte composition and concentration on the separation efficiency and resolution and mass spectrometric detection of illicit drugs in a capillary zone electrophoresis-electrospray ionization-time of flight mass spectrometry (CZE-ESI-TOF MS) system. The effect of phosphate, borate and Tris buffers on the separation and mass spectrometry response of a mixture of 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine, methadone, cocaine, morphine, codeine and 6-monoacetylmorphine was studied, in comparison with a reference ammonium formate separation buffer. Inorganic non-volatile borate and Tris buffers proved hardly suitable for capillary electrophoresis-mass spectrometry (CE-MS) analysis, but quite unexpectedly ammonium phosphate buffers showed good separation and ionization performances for all the analytes tested. Applications of this method to real samples of hair from drug addicts are also provided.

In-line solid-phase extraction-capillary electrophoresis coupled with mass spectrometry for determination of drugs of abuse in human urine

In-line solid-phase extraction-capillary electrophoresis coupled with mass spectrometric detection (SPE-CE-MS) has been used for determination of 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), codeine (COD), hydrocodeine (HCOD), and 6-acetylmorphine (6AM) in urine. The preconcentration system consists of a small capillary filled with Oasis HLB sorbent and inserted into the inlet section of the electrophoresis capillary. The SPE-CE-MS experimental conditions were optimized as follows: the sample (adjusted to pH 6.0) was loaded at 930 mbar for 60 min, elution was performed with methanol at 50 mbar for 35 s, 60 mmol L(-1) ammonium acetate at pH 3.8 was used as running buffer, the separation voltage was 30 kV, and the sheath liquid at a flow rate of 5.0 μL min(-1) was isopropanol-water 50:50 (v/v) containing 0.5% acetic acid. Analysis of urine samples spiked with the four drugs and diluted 1:1 (v/v) was studied in the linear range 0.08-10 ng mL(-1). Detection limits (LODs) (S/N = 3) were between 0.013 and 0.210 ng mL(-1). Repeatability (expressed as relative standard deviation) was below 7.2%. The method developed enables simple and effective determination of these drugs of abuse in urine samples at the levels encountered in toxicology and doping.

Development and validation of I-DNA1: a 15-Loci multiplex system for identity testing

This paper presents a system for the multiplex amplification of 15 loci, known as I-DNA1, which combines mini and midiSTR technology, with amplicon sizes ranging from 49 to 297 bp. I-DNA1 analyses all the STR loci included in the CODIS and the Interpol Standard Set of loci, nine of the ten European core loci and seven of the eight German core loci, making it suitable for use in identifying humans. Moreover, its high sensitivity and the small size of its amplicons mean that I-DNA1 is potentially highly useful for analysing highly degraded and/or very small DNA samples.