ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Objective: To investigate the specificity of endogenous metabolic profile in plasma of patients with occupational acute methyl acetate poisoning using non-targeted metabolomics. Methods: A total of six patients with occupational acute methyl acetate poisoning were selected as the poisoning group, while 10 healthy workers without occupational exposure history of chemical hazards in the same industry were selected as the control group using the judgment sampling method. Metabolites in patient plasma of the two groups were detected using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analysis was performed. Principal component analysis and partial least squares discriminant analysis were used to identify differential metabolites and analyze their metabolic pathways. Results: There were significant differences in metabolite profiles in patient plasma between poisoning group and control group. A total of 195 differentially expressed metabolites were screened in plasma of patients in poisoning group, including 119 upregulated and 76 downregulated metabolites. Lipid substances (lipids and lipid-like molecules) accounted for the highest proportion (21.5%). The differential metabolites of poisoning group were related to folate biosynthesis, amino acid metabolism, pyrimidine metabolism, sphingolipid biosynthesis and other metabolic pathways in plasma compared with the control group (all P<0.05). Conclusion: Occupational acute methyl acetate poisoning affects metabolism of the body. The folic acid biosynthesis, amino acid and lipid metabolism and other pathways may be involved in the occurrence and development of poisoning.
ABSTRACT
{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.
ABSTRACT
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.
ABSTRACT
OBJECTIVE: To explore the feasibility of simultaneous detection of 45 kinds of common organic compounds in workplace air by solvent desorption-gas chromatography method.METHODS: A total of 45 kinds of common organic compounds such as benzene,1,2-dichloroeyhane,n-hexane and trichloroethylene in workplace air were collected with activated carbon tube and desorbed with carbon disulfide,separated by capillary chromatographic column,and detected with flame ionization detector.RESULTS: There was good linear relationship in the selected range.The correlation coefficients was 0.999 92-0.999 99.The detection limit was 0.03-0.30 mg/L and the minimum detectable concentration range was 0.01-0.20 mg/m~3( sample volume was 3.00 L).The average desorption efficiencies was 75.4%-105.7%.The within-run and between-run relative standard deviations were 0.4%-6.7% and 1.8%-7.9%,respectively.The sampling efficiency was 91.9%-100.0%.CONCLUSION: The method is simple,high sensitivity and good precision,which can be used for simultaneous detection of 45 kinds of common coexisting organic compounds in workplace air.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Objective To analyze prevention and management of lymphatic fistula after cervical lymph node dissection in thyroid carcinoma.Methods Clinical data of 9 cases of lymphatic fistula following neck dissection were analyzed retrospectively from Jan.2004 to Apr.2009.Results Of the 9 cases,4 cases had chylous fistula(3 were on the leftside and 1 was on the rightside),1 case had chylotborax,1 case had pleural effusion lymph,and 3 cases showed light yellow lymph.AII patients were cured finally by conservative methods.Conclusions Most lymphatic fistula can be cured by non-surgical treatment.Surgeons need to be familiar with the anatomic structure of neck lymphatic vessels.
ABSTRACT
OBJECTIVE: To identify long-term outcomes and safety of transplantation of autologous peripheral blood stem cells (PBSC) for treating dilated cardiomyopathy.METHODS: A total of 38 cases with dilated cardiomyopathy received treatment at the Department of Cardiology, Guangdong General Hospital of Chinese People's Armed Police Forces, were selected, including 26 males and 12 females, aged 42-72 years, mean aged 56 years. Based on given standard therapy, 38 patients divided randomly into the transplantation group (n=20) and the control group (n=18). Patients in the transplantation group were received recombinant human granulocyte colony-stimulating factor (rhG-CSF) 300 ug/d once per day for 5 days to mobilize stem cells. At day 6, PBSC were collected with blood-cells separator and were transplanted through intracoroary way. The routine medication was performed in the control group. Blood routine test, hepatic function, renal function, glucose, triglyeride (TG), cholesterol, low density cholesterol (C-LDL), high density cholest- erol (C-HDL), uric acid (UA), creatine kinase (CK), isoenzyme of creatine kinase (CK-MB) and high sensitive C-reactive protein (hsCRP) were measured before and at months 6 and 12 after transplantation. All patients also received ultrasonic echocardiography, ECG Holter monitor and six-minute-walk test before and at 12 and 24 months after the procedure. Survival rate and incidence rate of heart incidents were compared. The study end-point was death from any cause. RESULTS: All patients received a 12-24 month follow-up with mean (18±6) months. One patient in the transplantation group received mitral valve replacement. One patient of the transplantation group and 2 of the control group died due to refractory heart failure. The blood routine test and biochemical indicators of the transplantation group had no significant differences among 6 months and 12 months after transplantation compared with control and pre-transplantation (P > 0.05). Six-minute-walking distance in the transplantation group significantly increased at 12 months after transplantation than pre-transplantation level, which was also higher than that of control patients (P < 0.05). The left ventricular ejection fraction (LVEF) was increased (P < 0.01). The left ventricular diastolic diameter (LVDd) decreased significantly in the transplantation group (P < 0.01). In the control group, improvement in LVEF and LVDd were observed, but there was no significant difference (P > 0.05). After 24 months of follow-up, the above-mentioned indexes had not improved in the transplantation group without significant differences. No malignant arrhythmias and severe side effects could be observed around transplantation and during 24 months follow-up. Survival was similar between the two groups during 24 months follow. CONCLUSION: Transplantation of mobilized autologous PBSC might be a safe and effective method for the treatment of dilated cardiomyopathy, which may improve the ventricular systolic function in a short-term, however, the long-term effects still uncertain.