Mass spectrometric data characteristics of commonly abused amphetamines with sequential derivatization at two active sites.

There have been reports on improved chromatographic parameters derived from the incorporation of sequential derivatization in preparing biological specimens for the analysis of opiates. This current study was designed to characterize the mass spectrometric data resulting from sequential derivatizations of commonly abused amphetamines (along with all commercially available deuterated analogs) containing two active sites, i.e.

Species identification of Kachuga tecta using the cytochrome b gene.

A DNA technique has been established for the identification to species level of tortoises. The test on the shell of the animal was used to identify samples from the species Kachuga tecta. A total of 100 tortoise shell specimens collected from the National Council of Agriculture (COA), Taiwan, were used in this study.

Mitochondrial DNA sequence alterations observed between blood and buccal cells within the same individuals having betel quid (BQ)-chewing habit.

There are hundreds of millions of betel quid (BQ) lovers widely spreading around the world. Compositions in BQ may generate reactive oxygen species, which would induce DNA damage. However, oral epithelial cells as well as blood have often been used as reference samples in comparison with the mitochondrial DNA (mtDNA) sequence of hairs.

Disease-Induced Anomalous Human Microsatellite DNA - Implication in Forensic DNA Typing.

Short tandem repeat (STR) markers adopted for forensic applications are generally stable and have been proved effective for the analysis of many archival pathology specimens and postmortem tissues. However, recent studies on STR typing of cancerous samples have shown misinterpreted profiles caused by two types of genetic alterations in tumor materials: microsatellite instability (MSI, contractions or expansions of a heterozygous allele) and loss of heterozygosity (LOH). Forensic STR typing of tumor material is unlikely; however, under rare circumstances, these may be the only samples available.

Pistol image retrieval by shape representation.

Databases have been used to record data in forensic science, such as fingerprints, shoeprints, and photos. In traditional databases, we use "text" as the "keyword" for retrieving data (text-keyword retrieval); however, in some applications, "text" is not proper to describe the searching target, and in this case, "image" plays an important role. In this paper, we use "image features" as the "keywords", and show its potential for building up a prototype of pistol image databases.

Enantiomeric determination of ephedrines and norephedrines by chiral derivatization gas chromatography-mass spectrometry approaches.

Concerned with variations in abuse potential and control status among various isomers of ephedrines and norephedrines, this study was conducted to develop an effective method for the simultaneous analysis of eight ephedrine-related compounds along with structurally similar cathinones. Among various approaches studied, a 60-m HP-5MS (0.25 mm i.

Enantiomeric determination of amphetamines: exploring a novel one-step solid-phase microextraction-based approach.

The recent advances in fiber manufacturing technology, solid-phase microextraction (SPME) is now widely studied for its effectiveness for the pretreatment of various categories of samples. This study explores a novel SPME approach for enantiomeric analysis of amphetamines, in which absorption/derivatization are accomplished in one step. Specifically, (S)-(-)-N-(Trifluoroacetyl)-prolyl chloride was adopted as the chiral derivatizing reagent and added directly into the sample matrix.

Mass Spectrometric Data of Commonly Abused Amphetamines and Their Derivatives - Cross Contribution of Ion Intensity between the Analytes and Their Isotopically Labeled Analogs.

With GC-MS as the preferred method and isotopically labeled analogs of the analytes as the internal standards (ISs) of choice for the analysis of drugs/metabolites in biological specimens, one important aspect associated with chemical derivatization (CD) is that the CD products derived from the analyte and the selected IS must generate ions suitable for designating the analyte and the IS; these ions cannot have significant crosscontribution (CC), i.e., contribution to the intensity of the ion designated for the analyte by the IS, and vice versa.

Characterization of the polymorphic repeat sequence within the rDNA IGS of Cannabis sativa.

The rDNA intergenic spacer (IGS) structure of Cannabis sativa contains six variable repeat motifs within a locus spanning 1387 base pairs. The degree of variation of the first three motifs was examined using 77 samples from cannabis samples. The samples originated from five seizures in Taiwan and seed stocks from six different countries.

The mask detection technology for occluded face analysis in the surveillance system.

The surveillance systems have been widely used in automatic teller machines (ATMs), banks, convenient stores, etc. For example, when a customer uses the ATM, the surveillance systems will record his/her face information. The information will help us understand and trace who withdrew money.

Simultaneous determination of amphetamine and methamphetamine enantiomers in urine by simultaneous liquid-liquid extraction and diastereomeric derivatization followed by gas chromatographic-isotope dilution mass spectrometry.

A simple, rapid, reliable, and economic analytical scheme starting with in situ liquid-liquid extraction and asymmetric (or diastereomeric) chemical derivatization (ChD) followed by gas chromatography (GC)-isotope dilution mass spectrometry (MS) is described for the simultaneous determination of D- and L-amphetamine (AP) and methamphetamine (MA) in urine which could have resulted from the administration of various forms of questioned amphetamines or amphetamines-generating drugs. By using L-N-trifluoroacetyl-1-prolyl chloride (L-TPC) as chiral derivatizing agent, resolutions of 2.2 and 2.

The safety helmet detection technology and its application to the surveillance system.

The Automatic Teller Machine (ATM) plays an important role in the modem economy. It provides a fast and convenient way to process transactions between banks and their customers. Unfortunately, it also provides a convenient way for criminals to get illegal money or use stolen ATM cards to extract money from their victims' accounts.

Establishing the rDNA IGS structure of Cannabis sativa.

The rDNA intergenic spacer (IGS) structure of Cannabis sativa was established and can be used for classification and identification of this species. In this study, DNA fragments of rDNA IGS were amplified by PCR from Cannabis sativa plant extracts and a 1387 bp fragment was obtained. DNA sequence analysis revealed six different repeat motifs.

Multi-resolution image fusion technique and its application to forensic science.

Image fusion is a process of combining two or more images into an image. It can extract features from source images, and provide more information than one image can. Multi-resolution analysis plays an important role in image processing, it provides a technique to decompose an image and extract information from coarse to fine scales.

Fingerprint pattern restoration by digital image processing techniques.

Fingerprint evidence plays an important role in solving criminal problems. However, defective (lacking information needed for completeness) or contaminated (undesirable information included) fingerprint patterns make identifying and recognizing processes difficult. Unfortunately.

Species identification of rhinoceros horns using the cytochrome b gene.

Material suspected of originating from species of Rhinoceros is frequently seized by forensic organizations investigating trade in endangered species. At present identification of the species is possible by DNA sequencing of the material, such as powdered rhinoceros horns. The unambiguous identification of rhino products using a 402 bp fragment of cytochrome b gene was investigated.

Evaluation of the DNA stability of forensic markers used in betel-quid chewers' oral swab samples and oral cancerous specimens: implications for forensic application.

Chewed betel-quid (BQ) residues are often considered vital biological evidence at crime scenes, since the human DNA extracted from the residues is actually from buccal epithelial cells and can be associated with suspects. BQ-chewing is also a risk factor for oral diseases and/or cancers. Archived medical oral-specimens can be used to identify specific individuals under adverse conditions, although STR markers are known to be unstable in various tumor tissues.

A highly polymorphic STR locus in Cannabis sativa.

We report on the first short tandem repeat (STR) locus to be isolated from the plant Cannabis sativa. The STR locus, isolated by a hybrid-capture enrichment procedure, was found to contain a simple sequence repeat motif of 6 bp. This 6 bp repeat motif showed no variation in repeat length but with minor variations in repeat unit sequences.

Sequence analysis of STR polymorphisms at locus ACTBP2 in the Taiwanese population.

A highly polymorphic sequence structure is reported in the human beta-actin related pseudogene 2 (ACTBP2) (SE33) locus in members of the Taiwanese Han population. A total of 100 unrelated members of the Taiwanese Han population were used in the study. Alleles that shared the same size but differ in their sequence are described to allow for inter laboratory sharing of data.

Isotopic analogs as internal standards for quantitative GC/MS analysis--molecular abundance and retention time difference as interference factors.

The following analyte/isotope-labeled internal standard (IS) systems are adapted to further study the interference phenomenon previously reported from our laboratory--the intensity ratio of the ion-pair designated for a specific analyte/2H-analog system increases as the solvent used to reconstitute the extraction/derivatization residue is increased: (a) Three analyte/2H-analog pairs with 2H-atoms positioned at allylic sites (butalbital, secobarbital, methohexital); (b) Two analyte/2H-analog pairs without these structural features (pentobarbital, phenobarbital); and (c) Two analyte/13C-analog pairs (butalbital, secobarbital). Major experimental parameters adapted in this study include: (a) Varying reconstitution solvent volume while keeping a constant analyte/IS concentration ratio; (b) Varying analyte/IS concentration ratio; (c) Varying gas chromatograph (GC) injection port temperature; and (d) Varying GC column temperature programming conditions, rendering difference in the degree of overlap of the peaks derived from the analyte and the 2H-analog. This study results in the following observations: (a) Changes in the intensity ratio of the ion-pair designated for a specific analyte/2H-analog system depend on molecular abundance, regardless of whether the 2H-atoms are positioned at active allylic positions or not--thus, ruling out hydrogen/deuterium exchange as the cause of the observed interference phenomenon; (b) Variations in GC injection port temperature do not alter the observed interference phenomenon-thus, ruling out chemical reactions at the injection port as the underlying cause; (c) Variations in peak-overlapping between the analyte and the 2H-analog, facilitated by changing GC column programming conditions, alter the observed interference phenomenon.

Causal factors of corporate crime in Taiwan: qualitative and quantitative findings.

Street crimes are a primary concern of most criminologists in Taiwan. In recent years, however, crimes committed by corporations have increased greatly in this country. Employing the empirical approach to collect data about causal factors of corporate crime, the research presented in this article is the first systematic empirical study concerning corporate crime in Taiwan.

Haplotype frequencies of nine Y-chromosome STR loci in the Taiwanese Han population.

Haplotype frequencies of nine Y-chromosome STR loci (DYS19, DYS385, DYS388, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393) in the Taiwanese Han population were established. A total of 183 unrelated individuals produced 162 haplotypes, of which 146 were unique, 1 was found in 5 individuals, 2 were found in 3 individuals and 13 were found in 2 individuals. The haplotype diversity (99.

Identification of tiny and thin smears of automotive paint following a traffic accident.

Three complementary methods in the order of stereomicroscopy, micro-FT-IR spectroscopy and solubility tests were used for the purpose of matching known and questioned paint samples in an auto accident case. Grayish green paint smears scattered on a silvery gray coated plastic bar were taken from a blue car and referred to as questioned samples. Green paint chips were collected as known samples from a green car.

A 3-D transformation to improve the legibility of license plate numbers.

In this paper, a novel three-dimensional transformation method for vehicle license plate number recognition is proposed. This method provides an efficient solution to normalize skew distorted vehicle license plate images. The Hough transform is used to estimate the license plate position and the normalization angle.

Mechanistic studies on the use of 2H- and 13C-analogues as internal standards in selected ion monitoring GC-MS quantitative determination--butalbital example.

As a part of our study on the use of isotopic analogues as the internal standard (IS) for the quantitation of drug analytes, this article reports on the performance characteristics of 2H5-butalbital and 13C4-butalbital with particular focus on (1) determining and comparing the effectiveness of the 2H- and 13C-analogues in serving as the ISs for quantitation; (2) understanding the "cross-contribution" phenomenon underlying the effectiveness of selected ion pairs used for quantitation purpose; and (3) examining whether the same characteristics, observed in our preliminary report for the secobarbital/2H5-secobarbital/13C4-secobarbital system, also exist in the butalbital/2H5-butalbital/13C4-butalbital system. Adapting similar procedures applied to our previous study on the secobarbital system, we observed that (1) both labeled analogues (13C4-butalbital and 2H5-butalbital) cause more significant cross-contributions to ions designated for butalbital than butalbital to the labeled analogues; (2) compared to 2H5-butalbital, 13C4-butalbital appears to cause less cross-contributions to ions designated for butalbital; (3) cross-contribution between the following ion pairs are minimal: m/z 200/196, 199/195, 185/181 (13C4-butalbital as the IS) and m/z 201/196 (2H5-butalbital as the IS). It is also concluded that the butalbital/2H5-butalbital system exhibits the same concentration dependency phenomenon observed in the secobarbital/ 2H5-secobarbital system, that is, ratios of ion pairs designated for these two isotopic analogues (resulting from routine gas chromatography-mass spectrometry protocol) increase as their concentrations are diluted.