The effects of glutamate transporters on synaptic plasticity in rat models of pilocarpine-induced status epilepticus were investigated. Male Wista rats ((304.06?13.79) g) were randomly divided into 5 groups, short-term seizures (SE) and its control (SC), long-term seizures (LE) and its control(LC), normal control (Sham) groups. Epilepsy rat models were induced by injection of pilocarpine(25 mg/kg, i.d.). Glutamate transporter inhibitor, DL-threo-benzyloxyaspartate (TBOA, 7.5 nmol,1 ?l) was microinjected into right side of hippocampus after 14 days of initial status epilepticus in SE and LE groups. The same volumes of artificial cerebrospinal fluid were injected into same side of hippocampus in SC and LC groups. Electroencephalographys (EEG) were detected in SE and SC groups after 2 h of drug injection. Long term potential (LTP) at perforant pathway and dentate gyrus(PP-DG) and EEG were recorded in LE and LC groups after two weeks of drug injection. Example of Fluoro-Jade-B staining in the rat brain was made at the end of electrophysiological experiment. The results showed that there was a significant decrease in theta band power of EEG in SE group compared with that of SC group (P 0.05). The slope of excitatory postsynaptic potential (EPSP) was significantly increased in LE group compared with that of LC group (P

OBJECTIVE: To develop a solvent desorption-gas chromatography method for detecting ethylene glycol monopropyl ether( EGME) in workplace air. METHODS: EGME in workplace air was captured by charcoal tubes and desorbed by methanol-methylene chloride(5∶ 95,V/V),separated by capillary chromatographic column,and detected by flame ionization detector. RESULTS: The good linear range of EGME was 1. 37-1 913. 80 mg/L,and the correlation coefficient was 0. 999 90. The detection limit was 0. 06 mg/L. The minimum detectable concentration was 0. 02 mg/m3.The average desorption efficiency was 97. 81%-104. 70%. The within-run relative standard deviation( RSD) was 1. 94%-2. 99%,and the between-run RSD was 3. 24%-4. 53%. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method could be used for detection of EGME in workplace air.

{L-End}Objective To establish a method for the simultaneous determination of dimethyltin (DMT), trimethyltin (TMT), diethyltin (DET), and triethyltin (TET) in human whole blood using high performance liquid chromatography-inductively coupled plasma-mass spectrometry (ICP-MS). {L-End}Methods The 1.0 mL of blood was added with 4.0 mL 65% aqueous solution (containing 6% acetic acid), extracted and separated by C₄ column (150 mm×3 mm×3 μm) using a mobile phase of methanol and 4% acetic acid aqueous solution (containing 0.25 mmol/L tropolone) at a volume ratio of 35∶65, and detected by ICP-MS. {L-End}Results The linear range of DMT, TMT, DET, and TET was 30.60-550.80, 29.00-522.00, 46.10-829.80, and 34.05-612.90 μg/L, respectively. All correlation coefficients were 0.999. The detection limit of DMT, TMT, DET and TET was 21.40, 20.30, 32.27 and 23.80 μg/L, respectively. The recovery rate was 81.9%-104.9%. The within-run and between-run relative standard deviation was 1.6%-6.9% and 0.1%-10.0%, respectively. The samples can be stored at -20 ℃ and 4 ℃ for at least three days. {L-End}Conclusion This method can be used for trace analysis of DMT, TMT, DET, and TET in whole blood.

OBJECTIVE: To establish a solvent desorption-gas chromatography method for simultaneous determination of 2-methoxyethyl acetate(2-MEA) and 2-ethoxyethyl acetate(2-EEA) in the workplace air. METHODS: 2-MEA and 2-EEA in workplace air were captured by charcoal tubes and desorbed with solution of 5. 00%(V/V) methanol-methylene chloride,separated through capillary chromatographic column,and then analyzed by gas chromatography-flameionization detector. RESULTS: The linear ranges of 2-MEA and 2-EEA were 1. 50-2 403. 84 and 1. 79-2 871. 20 mg/L,respectively.The correlation coefficient were 0. 999 8. The minimum quantification concentrations were 0. 20 and 0. 09 mg/m~3,respectively(3. 00 L sample). The average desorption efficiencies were 98. 08%-99. 67% and 94. 34%-99. 79%,respectively. The within-run relative standard deviations(RSD) were 1. 77%-3. 51% and 1. 72%-3. 01%,respectively.The between-run RSD were 2. 27%-4. 44% and 2. 31%-4. 19%,respectively. The samples could be stored at room temperature for at least 14 days. CONCLUSION: This method could be used for simultaneous sampling and quantitative detection of 2-MEA and 2-EEA in workplace air.

Objective To establish a rapid qualitative analysis method for volatile organic components in chemicals. Methods Headspace gas chromatography-mass spectrometry was used to qualitatively determine 19 volatile organic components, including benzene, 1,2-dichloroethane, and n-hexane, in chemicals. Different sample amounts, heating temperatures, heating times, and sample volumes were analyzed to assess their effects on detection results and optimize sampling conditions. Results Based on the set chromatography, the optimal sampling process of this method was as follows： 5.0 g sample in a 20.0 mL headspace bottle, incubated at 40 ℃ for 30 minutes in a constant-temperature drying incubator, and a 1.00 mL headspace gas injection. The within-run and between-run relative standard deviations of all components ranged from 0.00% to 21.05% and 0.00% to 33.33%, respectively. The samples stored in sealed glass containers were stable at room temperature for at least 60 days. Conclusion This method offers simplicity, good reproducibility, and stability, making it suitable for rapid qualitative analysis of volatile organic components in chemicals.

Objective To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of six aniline compounds (ADs) in workplace air. Methods GDH-1 air sampling tube was used to collect six co-existing ADs such as aniline, o-toluidine, N-methylaniline, m-methylaniline, p-methylaniline and N,N-dimethylaniline in the vapor and aerosol of workplace air. The samples were desorbed and eluted using a methanol solution containing 1.00% ammonia water, followed by separation on a C₁₈ chromatographic column and detection using a diode array detector. Results The quantification range of the method was 0.19 -253.50 mg/L, with the correlation coefficient of 0.999 9 for all six ADs. The minimum detection range was 0.02-0.06 mg/m³, and the minimum quantitation range was 0.04-0.19 mg/m³ [both calculated for a 15.0 L sample with a desorption (elution) solution volume of 3.00 mL]. The average desorption and elution efficiencies were 92.15%-104.41% (silica gel) and 94.29%-104.29% (filter membrane). The intra-assay relative standard deviation (RSD) ranged from 0.90%-9.72% (silica gel) and 0.57%-6.96% (filter membrane). The inter-assay RSD ranged from 2.03%-9.78% (silica gel) and 2.50%-8.62% (filter membrane). The samples were stable at room temperature for seven days. Conclusion This method can be used for the simultaneous determination of six ADs in workplace air.

Objective To investigate the method of portable gas chromatography-mass spectroscopy (GC-MS) for the determination of common volatile organic compounds in air.Methods The static volumetric method was used,with highly purified nitrogen gas as the diluents gas,to prepare the mixed standard gas of common volatile organic compounds with various mass concentrations.A portable GC-MS handheld probe was used for sampling and measurement,retention time and characteristic ion were used for qualitative analysis,and the full-scan mode was used for quantitative analysis.Results The correlation coefficient of 12 volatile organic compounds determined by this method was higher than 0.999.The minimum detection mass concentration was 0.02～0.12 mg/m3,and the minimum quantitative mass concentration was 0.07～0.40 mg/m3.The relative standard deviation of precision was 4.10％～12.50％;the relative deviation of acetone,benzene,methylbenzene,and dimethylbenzene was-13.56％,9.03％,-10.82％,and 8.67％,respectively.Conclusion Portable GC-MS method can be used for the qualitative analysis and quantification of volatile organic compounds in occupational hazard factors and provide technical supports for identification of occupational hazard factor.

Biotoxins, which include bacterial, fungal, marine, plant, and animal toxins, are widespread in living and occupational environments, posing potential threats to human health. Rapid detection of biotoxins in blood is crucial for preventing health hazards and enabling timely disease diagnosis and treatment. Biosensors and immunoassay technologies have critical advantages in the rapid detection of biotoxins in blood. Common biosensors, such as surface plasmon resonance biosensors and fluorescent biosensors, enhance sensitivity and reduce detection limits through signal amplification. Common immunoassay methods, such as colloidal gold immunochromatography, fluorescence immunochromatography, and chemiluminescence immunoassay, improve detection efficacy and sensitivity through specific antibody-antigen binding and nanotechnology. However, current rapid detection technologies of bitoxins in blood face challenges such as matrix interference and insufficient specificity, and they fall short in high-throughput detection of multiple toxins simultaneously. Future developments should focus on improving sample pretreatment, innovating signal amplification methods, enhancing specificity on recognition of elements, and designing portable detection devices and high-throughput platforms for simultaneous toxin analysis. These advancements aim to improve the sensitivity and reliability of detection methods, providing more accurate and convenient solutions for biotoxin detection in blood.

Objective To investigate the method of portable gas chromatography-mass spectroscopy (GC-MS) for the determination of common volatile organic compounds in air.Methods The static volumetric method was used,with highly purified nitrogen gas as the diluents gas,to prepare the mixed standard gas of common volatile organic compounds with various mass concentrations.A portable GC-MS handheld probe was used for sampling and measurement,retention time and characteristic ion were used for qualitative analysis,and the full-scan mode was used for quantitative analysis.Results The correlation coefficient of 12 volatile organic compounds determined by this method was higher than 0.999.The minimum detection mass concentration was 0.02～0.12 mg/m3,and the minimum quantitative mass concentration was 0.07～0.40 mg/m3.The relative standard deviation of precision was 4.10％～12.50％;the relative deviation of acetone,benzene,methylbenzene,and dimethylbenzene was-13.56％,9.03％,-10.82％,and 8.67％,respectively.Conclusion Portable GC-MS method can be used for the qualitative analysis and quantification of volatile organic compounds in occupational hazard factors and provide technical supports for identification of occupational hazard factor.

OBJECTIVE: To establish a methodology for simultaneous detection of chloromethyl methyl ether( CMME) and bis-chloromethyl ether( BCME) in workplace air by gas chromatography. METHODS: CMME and BCME in workplace air were collected with absorption solution which was also derivatization solution. The derivative products were extracted using n-hexane alkaline medium. The extracts were separated by capillary column and detected with electron capture detector.The quantification was performed by use of standard curves. RESULTS: The linearity ranges of CMME and BCME were2. 00-80. 00 and 1. 32-52. 80 ng,respectively. The correlation coefficients were both 0. 999 93. The minimum detectable concentrations were both 0. 030 μg / m3 and the minimum quantification concentrations were both 0. 100 μg / m3( 7. 50 L sample). The recovery rates were 99. 35%-101. 00% and 97. 99%-101. 70% respectively. The within-run relative standard deviations( RSD) were 2. 73%-4. 46% and 2. 61%-3. 82% respectively,and the between-run RSD were3. 10%-5. 50% and 3. 89%-5. 38% respectively. The sampling efficiencies were 92. 43%-96. 25% and 91. 43%-94. 03%respectively. The samples were stable at room temperature for at least 15 days. CONCLUSION: This method is suitable for simultaneous detection of CMME and BCME in workplace air.