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Lee C.S.,Sogang University | Lee C.S.,Scientific Investigation Laboratory | Sung T.M.,Scientific Investigation Laboratory | Kim H.S.,Scientific Investigation Laboratory | Jeon C.H.,Scientific Investigation Laboratory
Journal of Analytical and Applied Pyrolysis | Year: 2012

The forensic classification of soil samples was carried out by thermally assisted hydrolysis and methylation (THM) of soil organic matters (SOM) using pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). In this work, thirty-three THM derivatives were detected as SOM contained in <3 mg soil. The specific ions of the mass spectra were selected to separate and minimize the interference between SOM peaks. SOM data were normalized with the sum of peak areas to correct the amounts of SOM contained in the soil, and the chemometric approach based on principal component analysis (PCA), hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA) was employed to evaluate and compare the soil classification. The first seven principal components (PCs) accounted for 94.8% of total cumulate variance and these PCs were statistically determined by multiple comparisons (Tamhane's T2 and Dunnett's T3) for the post hoc test (p-value < 0.05) and were used to construct the LDA model. It was determined that multiple comparisons were a statistically good criterion for deciding on the number of PCs for the LDA model. It was also concluded that the discrimination model correctly classified 40 soil samples into six clusters with high accuracy. Furthermore, the eleven marker compounds were investigated according to the loadings of PCs and the normalized data. These results demonstrated that lignin, fatty acid and urea can be used as potentially useful compounds to characterize soil samples for forensic purposes. © 2012 Elsevier B.V. All rights reserved.


Lee C.S.,Sogang University | Lee C.S.,Scientific Investigation Laboratory | Jang I.,Sogang University | Hwangbo S.,Sogang University | And 2 more authors.
Bulletin of the Korean Chemical Society | Year: 2015

In tandem mass spectrometry, side-chain losses are known to provide information on the presence of certain amino acid residues, which can improve peptide identification. In this study, we examine whether side-chain losses also occur in free-radical-initiated peptide sequencing mass spectrometry (FRIPS MS). All four peptides examined here, i.e., ALPMHIR, YRPPGFSPFR, RPPGFSPYR, and YGGFLRRIRPKLK, showed extensive small group losses in the so-called (M• - X) region. Furthermore, peaks due to small group loss accompanying backbone fragmentations were also extensively observed. The observed small group losses, either radical or neutral side-chain losses, confirmed the presence of certain amino acids, even exhibiting signature peaks for isoleucine and leucine. In addition, mechanisms for small group losses in FRIPS MS are proposed. © 2015 Korean Chemical Society & Wiley-VCH Verlag GmbH & Co. KGaA.


Saito T.,Tokai University | Miura N.,Tokai University | Namera A.,Hiroshima University | Oikawa H.,GL Sciences Inc. | And 3 more authors.
Forensic Toxicology | Year: 2012

A rapid and specific method for simultaneous quantitation of organophosphates [fenitrothion (MEP), malathion (MAL), and phenthoate (PAP)], glyphosate (GLYP), and glufosinate (GLUF) in human serum and urine by gas chromatography-mass spectrometry (GC-MS) was validated. All targeted compounds, together with the internal standards [fenitrothion-d 6 (MEP-d 6) and dl-2-amino-3-phosphonopropionic acid (APPA)], were extracted from the serum and urine with a mixed-mode C-C 18 monolithic spin column. Extracted samples were derivatized with N-methyl-N-(tert- butyldimethylsilyl) trifluoroacetamide (MTBSTFA) containing 1% tert-butyldimethylchlorosilane (TBDMCS). Linear calibration curves for serum and urine spanned the ranges of 0.1-10.0 μg/ml for organophosphates, 10-100.0 μg/ml for GLYP, and 5-100.0 μg/ml for GLUF. Detection limits for serum and urine were 10 and 5 μg/ml for GLYP and GLUF, respectively, and quantitation limits for serum and urine were 10 and 5 μg/ml for GLYP and GLUF, respectively. Both detection and quantitation limits for serum and urine were 0.1 μg/ml for organophosphates. The intra-assay and interassay accuracy and precision (expressed as relative standard deviation, %RSD) evaluated for all compounds were within 96.5-109.5% and 5.9-13.1%, respectively. The recovery of organophosphates from serum and urine, spiked at concentrations of 0.1, 1.5, 5, and 9 μg/ml, ranged from 58.8 to 90.8%. Recovery of GLYP and GLUF from serum and urine, spiked at concentrations of 10 (serum) or 5 (urine), 15, 50, and 90 μg/ml, ranged from 2.6 to 6.9%. This method had a chromatographic run time of 16.0 min. The validated method was successfully applied to a clinical case of GLYP poisoning. © 2011 Japanese Association of Forensic Toxicology and Springer.


Saito T.,Tokai University | Yamagiwa T.,Tokai University | Yui Y.,GL Sciences Inc. | Miyazaki S.,GL Sciences Inc. | And 4 more authors.
Journal of Health Science | Year: 2010

A rapid gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the analysis of eperisone in serum using monolithic spin-column extraction. The linear concentration range for eperisone was 2-2500 ng/ml. The limit of detection was found to be 0.5 ng/ml. The average extraction recovery range was 92.8- 96.0%. The intra- and interday relative standard deviations (RSDs) of the concentrations were less than 12.6% and 12.5%, respectively. The accuracy of this method ranged from 95.0% to 98.3%. We successfully used this assay to analyze serum samples from an eperisone-overdose patient. Our method has some analytical advantages compared with previously reported gas chromatography (GC) and GC-MS methods, such as higher selectivity and sensitivity than GC with nitrogen-phosphorus detection and the avoidance of nonspecificity, the ability to use a smaller sample volume than that required for the GC-MS method, and a shorter sample preparation time than the previous solid-phase extraction (SPE) method.


Saito T.,Tokai University | Fukushima T.,Tokai University | Yui Y.,GL Sciences Inc. | Miyazaki S.,GL Sciences Inc. | And 4 more authors.
Analytical and Bioanalytical Chemistry | Year: 2011

We present a method based on monolitic spin column extraction and gas chromatography-mass spectrometry as an analytical method for screening diquat (DQ), paraquat (PQ), and fenitrothion in serum and urine. This method is useful for clinical and forensic toxicological analyses. Recovery of DQ, PQ, and fenitrothion from serum and urine, spiked at concentrations between 0.1, 2.5, 20, and 45 μg/ml, ranged from 51.3% to 106.1%. Relative standard deviation percentages were between 3.3% and 14.8%. Detection and quantitation limits for serum and urine were 0.025 and 0.05 μg/ml, respectively, for DQ, 0.1 and 0.1 μg/ml, respectively, for PQ, and 0.025 and 0.05 μg/ml, respectively, for fenitrothion. Therefore, these compounds can be detected and quantified in the case of acute poisoning. © 2011 Springer-Verlag.


Oka H.,Saitama University | Oka H.,Scientific Investigation Laboratory | Koyama T.,Saitama University | Hatano K.,Saitama University | And 2 more authors.
Bioorganic and Medicinal Chemistry Letters | Year: 2010

Synthesis of bi-fluorescence-labeled maltooligosaccharides for amylase assay was accomplished. Preliminary biological evaluation of both bi-fluorescence-labeled maltohexasaccharide and maltose using α-amylase was carried out, and the hexaosyl derivative showed unique variation on the basis of fluorescence resonance energy transfer (FRET). © 2010 Elsevier Ltd. All rights reserved.


Oka H.,Saitama University | Oka H.,Scientific Investigation Laboratory | Koyama T.,Saitama University | Hatano K.,Saitama University | Matsuoka K.,Saitama University
Bioorganic and Medicinal Chemistry | Year: 2012

A series of bi-fluorescence-labeled maltooligosaccharides that lead to fluorescence resonance energy transfer (FRET) was systematically synthesized. Effective FRETs were observed with all of the synthesized probes. Digestion of probes having tetra-, quintet-, hexa- or hepta-saccharidic chain lengths with human saliva α-amylase resulted in disappearance of FRET when an excitation wavelength of at 290 nm was used followed by detection at ca. 520 nm due to emission from the dansyl moiety. However, continuous FRET was observed when probes having di- or trisaccharidic chain lengths were used as substrates. In addition to the substrate characteristics based on saccharidic chain length, the reaction rates of digestion for the substrates by amylase were different and also depended on their saccharidic chain length. © 2011 Elsevier Ltd. All rights reserved.


Nakamoto A.,Scientific Investigation Laboratory | Nishida M.,Hiroshima University | Saito T.,Tokai University | Kishiyama I.,GL Sciences Inc. | And 4 more authors.
Analytica Chimica Acta | Year: 2010

A simple, sensitive, and specific method with gas chromatography-mass spectrometry was developed for simultaneous extraction and derivatization of amphetamines (APs) and 3,4-methylenedioxyamphetamines (MDAs) in human urine by using a monolithic silica spin column. All the procedures, such as sample loading, washing, and elution were performed by centrifugation. APs and MDAs in urine were adsorbed on the monolithic silica and derivatized with propyl chloroformate in the column. Methamphetamine-d5 was used as an internal standard. The linear ranges were 0.01-5.0 μg mL-1 for methamphetamine (MA) and 3,4-methylenedioxymethamphetamine (MDMA) and 0.02-5.0 μg mL-1 for amphetamine (AP) and 3,4-methylenedioxyamphetamine (MDA) (coefficient of correlation ≧0.995). The recovery of APs and MDAs in urine was 84-94%, and the relative standard deviation of the intra- and interday reproducibility for urine samples containing 0.1, 1.0, and 4.0 μg mL-1 of APs and MDAs ranged from 1.4% to 13.6%. The lowest detection limit (signal-to-noise ratio ≧ 3) in urine was 5 ng mL-1 for MA and MDMA and 10 ng mL-1 for AP and MDA. The proposed method can be used to perform simultaneous extraction and derivatization on spin columns that have been loaded with a small quantity of solvent by using centrifugation. © 2009 Elsevier B.V. All rights reserved.


Eom H.Y.,Chung - Ang University | Kim H.-S.,Chung - Ang University | Kim H.-S.,Scientific Investigation Laboratory | Han S.B.,Chung - Ang University
Mass Spectrometry Letters | Year: 2014

An advanced and reliable high performance liquid chromatography (HPLC)/ultraviolet detector (UV)/ion-trap timeof- flight (IT-TOF) mass spectrometry was developed for the simultaneous quantification of 19 marker compounds in Bangpoong- tong-sung-san (BPTS), a traditional oriental prescription. Various parameters affecting HPLC separation and IT-TOF detection were investigated, and optimized conditions were identified. The separation was achieved on a Capcell PAK C18 column (1.5 mm × 250 mm, 5 μm particle size) using a gradient elution of acetonitrile and water containing 0.1% formic acid at a flow rate of 0.1 mL/min. The column temperature was maintained at 40°C and the injection volume was 2 μL. IT-TOF system was equipped with an electrospray ion source (ESI) operating in positive or negative ion mode. The optimized electrospray ionization parameters were as follows: ion spray voltage, +4.5 kV (positive ion mode), or -3.5 kV (negative ion mode); drying gas (N2), 1.5 L/min; heat block temperature, 200°C. Automatic MSn (n = 1~3) analyses were carried out to obtain structural information of analytes. Elemental compositions and their mass errors were calculated based on their accurate masses obtained from a formula predictor software. The marker compounds in BPTS were identified by comparisons between MSn spectra from standards and those from extracts. Moreover, the libraries of MS2 and MS3 spectra and accurate masses of parent and fragment ions for marker compounds were constructed. The developed method was successfully applied to the BPTS extracts and identified 17 out of 19 marker compounds in the BPTS extracts.


PubMed | Scientific Investigation Laboratory
Type: Journal Article | Journal: Shinrigaku kenkyu : The Japanese journal of psychology | Year: 2012

The effect of self-relevance of a non-critical item in the Concealed Information Test (CIT) was investigated. Respiration, skin conductance response (SCR), heart rate, and normalized pulse volume were recorded while performing the CIT using a stimulus set composed of 4 items (with one self-relevant item). Thirty participants were instructed to recognize one item as critical and the remaining items as non-critical (positive group), and 33 participants were instructed to recognize all items as non-critical (negative group). In the positive group, a differential reactivity was observed between the critical and non-critical items, despite the self-relevance of the non-critical item. In the negative group, a differential reactivity between the self-relevant and non-self-relevant items was observed for SCR only. However, when individual data were analyzed, there was a differential reactivity between self-relevant and non-self-relevant items on physiological measures other than SCR for some participants in the negative group. These results suggest that the self-relevance of a non-critical item might cause false positive results in negative participants, particularly when only SCR is used to assess differential reactivity.

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