Determination of nitrogen oxides in the air of workplace by ion chromatography / 中华劳动卫生职业病杂志

Objective@#Improvement the method of nitrogen oxide sampling, analysis and detection in workplace air.@*Methods@#Absorption and collection with sodium carbonate-sodium bicarbonate buffer solution, analysised by ion chromatography, anion column AS23, column temperature 30 ℃.@*Results@#The linearity of the nitrite ion in the corresponding mass concentration range 0~90.0 μg/ml was good (Nitrogen dioxide in 0~120.0 mg/m3) , correlation coefficient>0.999 5. The detection limit was 0.16 μg/ml, The minimum detection concentration was 0.11 mg/m3 with the sampling volume 7.5 L.@*Conclusion@#The method has good accuracy, high sensitivity, with directing injection and no pre-treatment, and can popularize in general laboratories, and can satisfy the determination of nitrogen oxides in the air of workplace.

Ion Chromatography Method of Four Carboxylic Acids in Workplace Air / 中华劳动卫生职业病杂志

Objective@#To assess psychological acceptance and occupational stress of medical staff, analyze the relationship among personality, psychological acceptance and occupational stress and discuss the direct or indirect effects of personality to occupational stress.@*Methods@#The gaseous four kinds of carboxylic acids in the workplace air were simultaneously collected by silica gel tube, and then desorbed by deionized water and eluted by ion chromatograph. The the content was detected by conductivity detector.@*Results@#The linear relationship was good in the concentration range of about 0~140 mg/L. The correlation coefficient r>0.999, and the maximum detection limit was 4.5 μg/mL. The sampling efficiency of the four carboxylic acids ranges from 96.10%~100.27%. Through the sample added recovery experiments, the low and high content of the silicone tube samples were detected; and the range of desorption efficiency was 82.18%~100.12%; the range of precision was 0.70%~3.71%.@*Conclusion@#This method adopts deionized water to desorb samples, and the application of ion chromatography detection have reached the requirements of《Guidelines for the establishment of occupational health standards, Part 4: Determination of chemical substances in workplace air》, which can be used in four kinds of workplace air detection of carboxylic acid compounds.

Determination of p-Anisidine in workplace air by HPLC / 中华劳动卫生职业病杂志

Objective@#To establish an HPLC method for determining p-Anisidine in workplace air.@*Methods@#An C18 capillary column was used with the detection wavelength of 240 nm, the methanol solution (v/v=62:38) as mobile phase, the flow rate was 0.9 ml/min, and the injection volume was 20 μl.@*Results@#The linear range (μg/ml) for p-Anisidine was 0~100; correlation coefficient was 0.999 7; the detection limit was 0.15 μg/ml; the average precision of RSD was 4.4%. The sampling efficiency was more than 95% using silicone tube as sampling filter. Sample can be stored at room temperature for more than 7 d.@*Conclusion@#the method appered to be accurate, simple, sensitive and reliable, also have a high sampling efficiency, and can be usd to determine p-anisidine in workplace air simultaneously.

The application value of CT and MRI on children’s vein of Galen malformation / 实用放射学杂志

Objective To investigate the clinical application value of CT and MRI on the children’s vein of Galen malformation (VGAM).Methods CT and MRI images of 10 children cases with VGAM were analyzed retrospectively.Results CT and MRI find-ings:10 cases with dilatation of the vein of Galen,8 cases with straight sinus dilation,6 cases with dilation of confluence sinus,and 6 cases with other sinus dilatation.Blood supply vessels:basilar artery in 6 cases,posterior cerebral artery in 2 cases,anterior cerebral artery in 1 case and other vascular in 1 case.Complications:bleeding in 4 cases,thrombosis in 2 cases,and calcification in 2 cases. Conclusion CT and MRI can confirm the diagnosis of children’s VGAM,and abnormal blood-supply vessels.CT has advantages of observation of calcifications,and MRI has advantages of observation of hemorrhage and thrombosis.

Determination of thiodiglycolic acid in urine with gas chromatography-mass spectrometer / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a rapid determination method with gas chromatography-mass spectrometer (GC-MS) for thiodiglycolic acid (TDGA), a vinyl chloride (VCM) biomarker.</p><p><b>METHODS</b>A high- sensitivity determination method was established using a moderate methyl esterification instead of methyl esterification of highly toxic diazo reaction.</p><p><b>RESULTS</b>The standard curve regression linear equation of the method was: y=8460.5x-4758.2, the linear coefficient was 0.999 7, the minimum quantity concentration was 2.0 µg/L, the range of precision value was 0.81%-2.38%, and the average recovery of standard addition was 99.0%-102.9%.</p><p><b>CONCLUSION</b>This method reduces the risk of traditional methyl esterification, improves the determination sensitivity compared with the GC-FPD method, and meets the determination requirement of TDGA.</p>

Determination of four biogenic amine metabolites in urine by high-performance liquid chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish a method for simultaneously determining vanilmandelic acid (VMA), 5-hydroxyindoleacetic (5-HIAA), 3, 4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in urine by high-performance liquid chromatography (HPLC).</p><p><b>METHODS</b>After being filtered with a 0.45 µm membrane syringe filter, the urinary samples were injected directly into the HPLC system using a C18 chromatographic column and a fluorescence detector. The excitation and emission wavelengths were chose as 280 nm and 315 nm, respectively, and the urinary samples were carried with a mobile phase of methanol-0.1 mol/L phosphate buffered solution (V/V = 20:80) at a flow rate of 1.0 ml/min and an injection volume of 20 µl.</p><p><b>RESULTS</b>Using the method reported here, the correlation coefficients of VMA, 5-HIAA, DOPAC, and HVA were 0.9999, 0.9998, 0.9997, 0.9999, respectively, over linear ranges of 0-2.5, 0-2.0, 0-2.0, and 0-2.5 µg/ml, the minimum detectable concentrations were 0.006, 0.008, 0.012, and 0.0082 µg/ml, the average precisions were 4.2%, 3.7%, 4.9%, and 3.6%, and the recovery rates were 91%∼102%, 93%∼101%, 94%∼101%, and 89%∼ 102%.</p><p><b>CONCLUSION</b>This determination method is simple, efficient, accurate, and sensitive for the simultaneous detection of VMA, 5-HIAA, DOPAC, and HVA in urine.</p>

Determination of Lead in Air With Hydride Generation Atomic Fluorescence Spectrophotometry / 环境与健康杂志

Objective To establish a method to determine lead in air. Methods The filter film used to collect the lead in air was digested with acid followed by adding mixed solution of potassium ferricyanide,oxalic acid and hydrochloric acid, then double ways atomic flurescence spectrophotometry was employed to determine lead. Results The optimal concentration of hydrochloric acid, potassium ferricyanide and oxalic acid were 0.12 mol/L, 8 g/L and 0.4 g/L respectively. The detection limit of lead was 1 ?g/L, the relative standard deviation was 2.5%. The recovery rates ranged from 90% to 95%, the linar range was 10-80 ?g/L. Conclusion This method was simple, rapid, accurate and sensitive. It was suitable for determining lead in air.