No abstract available.
Diagnosis ; Gas Chromatography-Mass Spectrometry

No abstract available.
Gas Chromatography-Mass Spectrometry* ; Mass Screening* ; Neuroblastoma*

Because of the exist of complex matrix, the confirming indicators of qualitative results for toxic substances in biological samples by chromatography-mass spectrometry are different from that in non-biological samples. Even in biological samples, the confirming indicators are different in various application areas. This paper reviews the similarities and differences of confirming indicators for the analyte in biological samples by chromatography-mass spectrometry in the field of forensic toxicological analysis and other application areas. These confirming indicators include retention time （RT）, relative retention time （RRT）, signal to noise （S/N）, characteristic ions, relative abundance of characteristic ions, parent ion-daughter ion pair and abundance ratio of ion pair, etc.
Chromatography ; Forensic Toxicology ; Gas Chromatography-Mass Spectrometry ; Mass Spectrometry

Acetates ; urine ; Chromatography, Gas ; Gas Chromatography-Mass Spectrometry ; Humans

No abstract available.
Gas Chromatography-Mass Spectrometry* ; Humans* ; Steroids*

Metabonomics involves the unbiased quantitative and qualitative analysis of the complete set of metabolites present in cells, body fluids and tissues (the metabolome) based on modern analytic technique with high throughput, high sensitivity, and high resolution. Gas chromatography-mass spectrometry (GC-MS) is used to gain qualitative results of detected metabolites for biological samples as it provides superior distinguishability, detection sensitivity and integrated standard mass spectrometry library. In this article, the historic developments of GC-MS and its application in metabonomics in the past several years were reviewed. Firstly, the classification and the derivative methods of GC-MS were introduced. Subsequently, sample pretreatment process, qualitative and quantitative analysis and data analysis during detecting metabolites by GC-MS were introduced, then its application in microorganism, plant and disease diagnosis was systematically summarized. Finally, the problems in metabonomics study based on GC-MS and the research prospect in the future were discussed.
Gas Chromatography-Mass Spectrometry ; methods ; Metabolomics ; methods

Objective: To establish a method for detection of 6 BTEXs in urine by Purge and Trap-Gas Chromatography-Mass Spectrometry. Methods: The urine sample need not be diluted, but directly purge and trap in the bottle, separated by gas chromatography column, then simultaneously analyzed by retention time locking (RTL) method and selective ion scanning mode (SIM) . Results: The linear range of 6 BTEXs in urine was good, the correlation coefficient was between 0.997 4 and 0.998 9. The minimum quantification limits was 0.010-0.036 μg/L. The precision was 1.9%-4.7%, and the recovery was 93.1%-101.9%. Conclusion: The method has the advantages of wide linear range, high sensitivity and recovery. It is suitable for the determination of 6 BTEXs in urine of low level occupational-exposed or non-exposed population.
Gas Chromatography-Mass Spectrometry/methods* ; Occupational Exposure

Objective To establish a method for determination of the azide ions in blood by gas chromatography-mass spectrometry （GC-MS） following pentafluorobenzyl derivatization. Methods A blood sample of 0.2 mL was placed into a 10 mL glass test tube, and the internal standard sodium cyanide, derivatization reagent pentafluorobenzyl bromide and catalyst tetradecyl benzyl dimethyl ammonium chloride were added in turn. After vortex mixing, the mixture was heated with low-power microwave for 3 min. After centrifugation, the organic phase was taken for GC-MS analysis. Results The azide ions in blood had a good linear relationship in the mass concentration range of 0.5 to 20 μg/mL. The lowest detection limit was 0.25 μg/mL and the relative recovery was 91.36%-94.58%. The method was successfully applied to a case of death from sodium azide poisoning. The mass concentration of azide ions in the blood of the dead was 11.11 μg/mL. Conclusion The method developed in this paper has strong specificity and is easy to operate, which is suitable for the rapid detection of azide ions in blood.
Azides ; Gas Chromatography-Mass Spectrometry ; Humans ; Ions

Objective To study the identification method for 4'-F-4-methylaminorex （4'-F-4-MAR） in samples without reference substance. Methods Gas chromatography-mass spectrometry （GC-MS）, ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry （UPLC-QTOF-MS）, nuclear magnetic resonance （NMR） and Fourier transform infrared （FTIR） were comprehensively used for the structure identification of 4'-F-4-MAR in samples. Results Under the positive electrospray ionization （ESI⁺） mode, quasi-molecular ion in the first order mass spectrometry of the unknown compound was 195.092 6 and its molecular formula was inferred to be C₁₀H₁₁FN₂O. The fragment ions in the mass spectrometry of the unknown compound were compared with the related fragment ions of 4,4'-dimethylaminorex （4,4'-DMAR） in literature. It was found that the main fragment ions of the unknown compound were all 4 bigger than the corresponding fragment ions of 4,4'-DMAR. Therefore, the unknown compound was inferred to be a 4,4'-DMAR analogue with a methyl substituted by a fluorine in the benzene ring. The equivalent protons at δ=7.30 and δ=7.06 in ¹H-nuclear magnetic resonance （¹H-NMR） spectra and the characteristic spin-spin coupling constants （¹J_C-F=245.2 Hz, ²J_C-F=21.3 Hz, ³J_C-F=8.1 Hz） for ¹³C-¹⁹F interactions in carbon spectra, further proved that the fluorine substituted methyl at the para-position of the benzene ring. Finally, the unknown compound was determined as 4'-F-4-MAR. Conclusion A method that comprehensively used the identification materials 4'-F-4-MAR in GC-MS, UPLC-QTOF-MS, NMR and FTIR is established and the fragmentation mechanism of fragmentation ions of 4'-F-4-MAR created under the two modes -- electron impact （EI） and electrospray ionization under collision induced dissociation （ESI-CID） is deduced. The information will assist forensic science laboratories in identifying this compound or other substances with similar structure in their case work.
Aminorex ; Chromatography, High Pressure Liquid ; Gas Chromatography-Mass Spectrometry ; Mass Spectrometry ; Nitroimidazoles ; Spectrometry, Mass, Electrospray Ionization

Objective To establish an ion chromatography method for the salt form determination of new psychoactive substances （NPS）. Methods The method of conducting qualitative and quantitative analysis of six types of organic acid ions （acetate ion, tartrate ion, maleate ion, oxalate ion, fumarate ion, citrate ion） and five types of inorganic anions （fluoride ion, chloride ion, nitrate ion, sulfate ion, phosphate ion） in NPS sample by ion chromatography was developed. The salt forms of 222 seized NPS samples （103 samples with synthetic cannabinoids, 81 samples with cathinones, 44 samples with phenylethylamines, 12 samples with tryptamines, 7 samples with phencyclidines, 6 samples with piperazines, 2 samples with aminoindenes, 26 samples with fentanyls and 43 samples with other types of NPS） were analyzed by this method. Results Each anion had good linearity in the corresponding linear range, the correlation coefficients （r） were greater than 0.999, the limits of detection were 0.01-0.05 mg/L, and the limits of quantitative were 0.1-0.5 mg/L. Except that 5F-BEPIRAPIM was hydrochloride, the salt forms of the other 102 synthetic cannabinoids were all base. The salt form of 81 cathinone samples, 44 phenylethylamine samples, 7 phencyclidine samples and 2 aminoindene samples were all hydrochloride. The salt forms of tryptamine samples included base, hydrochloride, fumarate and oxalate. The salt forms of piperazine samples included base and hydrochloride. The salt forms of fentanyl samples and samples of other types included base, hydrochloride and citrate. Conclusion Ion chromatography is a simple, accurate and efficient method for determining the salt form of NPS samples, which makes the qualitative and quantitative conclusions of NPS more scientific and rigorous.
Chromatography, Liquid ; Gas Chromatography-Mass Spectrometry ; Ions ; Psychotropic Drugs/chemistry*