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Mustafa Erinc Sitar et al.
Amino acids, 47(9), 1983-1993 (2015-04-30)
Free, non-protein bound asymmetrically guanidine-dimethylated arginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis. Human erythrocytic membrane comprises considerable amounts of large (>50 kDa) ADMA-containing proteins. Location in the erythrocyte membrane and identity and physiological functions of ADMA-containing...
S Valtier et al.
Journal of analytical toxicology, 19(6), 375-380 (1995-10-01)
Deuterium-labeled analogues are available for a variety of drugs, but the amphetamines (amphetamine and methamphetamine) have more options available than any other drug. The analytical method and circumstances of its use can have a significant impact on the decision of...
Qi Zhang et al.
Applied and environmental microbiology, 81(13), 4339-4350 (2015-04-19)
Lanthionine-containing peptides (lanthipeptides) are a rapidly growing family of polycyclic peptide natural products belonging to the large class of ribosomally synthesized and posttranslationally modified peptides (RiPPs). Lanthipeptides are widely distributed in taxonomically distant species, and their currently known biosynthetic systems...
J Röhrich et al.
Forensic science international, 215(1-3), 3-7 (2011-05-06)
4-Fluoroamphetamine (4-FA) was detected in the blood and urine of two individuals suspected for driving under the influence (DUI). The test for amphetamines in urine subjected to immunoassay screening using the CEDIA DAU assay proved positive. Further investigations revealed a...
F F Hsu et al.
Analytical biochemistry, 216(2), 401-405 (1994-02-01)
We report an isotope dilution mass spectrometry method using capillary gas chromatography negative ion chemical ionization for the determination of cortisol in human plasma. Cortisol was derivatized with pentafluoropropionic anhydride at room temperature and measured by selected ion monitoring of...
Panagiota Nikolaou et al.
Journal of pharmaceutical and biomedical analysis, 102, 25-32 (2014-09-23)
A sensitive and accurate gas chromatography-mass spectrometric method was developed and validated for the simultaneous determination of levetiracetam and lamotrigine in whole blood. A solid-phase extraction (SPE) procedure using HF Bond Elut C18 columns followed by derivatization using N-methyl-N-tert-butyldimethylsilyl-trifluoroacetamide (MTBSTFA)...
Derivatization and gas chromatographic determination of some biologically important acids in cerebrospinal fluid.
E Watson et al.
Analytical biochemistry, 59(2), 441-451 (1974-06-01)
Ju-Yeon Moon et al.
Journal of lipid research, 52(8), 1595-1603 (2011-05-24)
Estrogen metabolites play important roles in the development of female-related disorders and homeostasis of the bone. To improve detectability, a validated gas chromatography-mass spectrometry (GC-MS) method was conducted with two-phase extractive ethoxycarbonlyation (EOC) and subsequent pentafluoropropionyl (PFP) derivatization was introduced....
Y S Oh-Shin et al.
Journal of chromatography. A, 769(2), 285-291 (1997-05-09)
A rapid and simple gas chromatographic method for the simultaneous determination of malathion, parathion, fenitrothion, diazinon and carbaryl in drinking water is presented. A fused-silica SE-54 column was used for the separation of the insecticides and was split into two...
J M Halket et al.
Journal of chromatography, 562(1-2), 279-287 (1991-01-02)
A simple procedure based upon capillary column gas chromatography-mass spectrometry (GC-MS) is described for the detection and determination of isatin (indole-2,3-dione) in body fluids and tissues. After addition of 5-methylisatin as internal standard to urine or tissue homogenates, organic extracts...
I Jakasa et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 811(2), 177-182 (2004-11-04)
We developed a sensitive method for determination of polyethylene glycols (PEGs) of different molecular weight (MW) in the human stratum corneum (SC) obtained by tape stripping. The analysis is based on derivatization with pentafluoropropionic anhydride (PFPA) and gas chromatography-electron capture...
M Kohno et al.
Biochemical and biophysical research communications, 140(1), 448-454 (1986-10-15)
This is the first report to identify 1,2,3,4-tetrahydroisoquinoline and 1-methyl-1,2,3,4-tetrahydroisoquinoline as endogenous amines from non-treated rat brain. The detection was performed by coupled gas chromatography - multiple ion detection, using heptafluorobutyric anhydride and pentafluoropropionic anhydride as derivatizing reagents. These amines...
C Kutzer et al.
Journal of chromatographic science, 35(1), 1-6 (1997-01-01)
A new method for the simultaneous determination of hemoglobin adducts from aromatic amines and tobacco-specific nitrosamines (TSNA) is described. After mild base-catalysed hydrolysis releasing aromatic amines and the TSNA adduct 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB), the extraction, cleanup, and concentration are performed by...
R E Aderjan et al.
Journal of analytical toxicology, 17(1), 51-55 (1993-01-01)
A method for the simultaneous detection and quantification of cocaine and benzoylecgonine from human blood and urine has been developed. Cocaine and benzoylecgonine were extracted from blood and urine with solid-phase columns containing C18 packing material. Clean, emulsion-free extracts were...
Julia L Drewes et al.
Journal of neurovirology, 21(4), 449-463 (2015-03-18)
Activation of the kynurenine pathway (KP) of tryptophan catabolism likely contributes to HIV-associated neurological disorders. However, KP activation in brain tissue during HIV infection has been understudied, and the effect of combination antiretroviral therapy (cART) on KP induction in the...
Iain M McIntyre et al.
Journal of analytical toxicology, 39(2), 156-159 (2014-11-29)
A 20-year-old man, a college student, became unresponsive in front of his girlfriend. He was known to consume alcohol and take an unknown drug at some point while in attendance at a local music festival earlier in the day/evening. Upon...
J L Villamor et al.
Journal of analytical toxicology, 29(2), 135-139 (2005-05-21)
A new gas chromatography-mass spectrometry method for the simultaneous identification and quantitation of amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethamphetamine (MDEA) in hair is proposed. Hair was hydrolyzed in 1 M NaOH at 40 degrees C, subjected...
Bettina Mönch et al.
Forensic science international, 226(1-3), 202-207 (2013-02-19)
The validation of a robust quantification procedure for EtG in hair using GC-NCI-MS is presented. Aqueous extraction is followed by complete lyophylization of the extract and derivatization with pentafluoropropionic anhydride (PFPA) under controlled temperature and duration. Clean-up of extracts was...
Arslan Arinc Kayacelebi et al.
Amino acids, 47(9), 1893-1908 (2015-06-03)
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis, whereas L-arginine (Arg) and L-homoarginine (hArg) serve as substrates for NO synthesis. ADMA and other methylated arginines are generally believed to exclusively derive from guanidine (N (G))-methylated arginine...
K Takamoto et al.
European journal of biochemistry, 228(2), 362-372 (1995-03-01)
An accurate carboxy-terminal sequencing method has long been sought to complement the Edman degradation procedure for amino-terminal amino acid sequence analysis. The method presented here is a unique and simple method to partly fulfill the needs. Exposure of a polypeptide...
E Ballesteros et al.
Analytical chemistry, 65(13), 1773-1778 (1993-07-01)
A new analytical method that combines on-line derivatization-extraction and gas-liquid chromatography for the determination of N-methylcarbamates is reported. The hydrolysis products of N-methylcarbamates (phenols) are derivatized and extracted in a continuous fashion using pentafluoropropionic anhydride (derivatizing reagent) in n-hexane as...
Calum Morrison et al.
Chirality, 23(7), 519-522 (2011-04-21)
The aim of this study was to develop a chiral gas chromatographic method for the separation of compounds likely to be found in the EMDE synthesis of methylamphetamine, a heavily abused stimulant drug. Here we describe the separation of the...
Dilek Battal et al.
Therapeutic drug monitoring, 37(6), 805-811 (2015-05-21)
Mescaline, the primary psychoactive chemical in peyote cactus, has been consumed for thousands of years in ancient religious ceremonies. The US military wanted to determine if mescaline intake was a problem for personnel readiness. Twenty thousand seventeen urine specimens negative...
Karim M Abdel-Hay et al.
Forensic science international, 240, 126-136 (2014-05-14)
A series of seven regioisomeric bromodimethoxy benzyl piperazines including the designer benzylpiperazine (4-bromo-2,5-dimethoxybenzylpiperazine) were synthesized and their analytical profiles evaluated using GC-MS and FT-IR. The mass spectra for the seven regioisomeric bromodimethoxy benzyl piperazines are almost identical with only the...
Ma Paz Lorenzo et al.
Journal of pharmaceutical and biomedical analysis, 107, 480-487 (2015-02-14)
Gestational Diabetes Mellitus (GDM) is defined as glucose intolerance with onset or first recognition during pregnancy. It is affecting approximately up to 14% of all pregnancies with an increasing tendency. GDM has been related to relevant short-term and long-term health...
C Jurado et al.
Forensic science international, 145(2-3), 161-166 (2004-09-29)
This paper describes a procedure for the detection and quantification of ethyl-glucuronide (EtG) in hair samples. During method development the efficacy of extraction of EtG from hair was compared in four extraction methods: (a) methanol; (b) methanol:water (1:1); (c) water;...
Marcus May et al.
Amino acids, 47(9), 1847-1852 (2015-02-07)
Increased cardiovascular risk associated with obesity cannot be fully explained by traditional risk markers. We therefore assessed plasma and interstitial concentrations of the novel cardiovascular risk biomarker homoarginine (hArg) in 18 individuals without signs of cardiovascular disease, including 4 morbidly...
Simultaneous determination of 3,4-dihydroxyphenylacetic acid and homovanillic acid in milligram amounts of rat striatal tissue by gas-liquid chromatography.
E Watson et al.
Life sciences, 15(12), 2167-2178 (1974-12-15)
R G Macfarlane et al.
Journal of chromatography, 532(1), 1-11 (1990-10-26)
Phenylalanine, tyrosine and dihydroxyphenylalanine (DOPA) were identified unambiguously and quantitatively determined in single ventral thoracic nerve cords from the locust, Schistocerca gregaria, by gas chromatography-negative-ion chemical ionisation mass spectrometry. Deuterium-labelled analogues of each compound were added to a single ventral...
Colton H F Wong et al.
Drug testing and analysis, 4(12), 1028-1033 (2012-06-27)
Gas chromatography-mass spectrometry (GC-MS) analysis after heptafluorobutyric anhydride (HFBA) derivatization was one of the published methods used for the quantification of ephedrine (EP) and pseudoephedrine (PE) in urine. This method allows the clear separation of the derivatized diastereoisomers on a...
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