In present study, the sample pretreatment condition was optimized, the relative standard deviations of intra-day and inner-day, the spiked samples and its recovery were evaluated for analyzing the accuracy of the proposed method. Conclusion This method has proved to be simple, efficient and highly sensitivity, it can be utilized for butanone detection in occupational population.Objective To establish an ultra-high performance liquid chromatography method for the determination of mifepristone in the air of workplaces. Methods From January to July 2018, glass fiber filter membrane was used to collect mifepristone in the workplace air, eluted with acetonitrile/water solution, and determined by ultra-high performance liquid chromatography-UV method. Results The detection limit of mifepristone determination method was 0.005 μg/ml, the lower limit of quantification was 0.015 μg/ml, and the lowest detection concentration was 0.14 μg/m(3) (calculated by collecting 75 L air samples) . MCC950 manufacturer The concentration of mifepristone has a good linear relationship between 0.015-40.24 μg/ml, r=0.9999. The accuracy and elution efficiency of the method were calculated based on the recovery rate, ranging from 92.7% to 100.0%. The average sampling efficiency was 99.6%-100.0%. The intra-assay precision of the method was 0.92% to 5.41%, and the inter-assay precision was 0.89% to 6.25%. The sample could be stored stably for 3 days at 4°C. Conclusion The ultra-high performance liquid chromatography method for determination of mifepristone is easy to operate, and its indicators meet the requirements of GBZ/T 201.4-2008 “Guidelines for the Establishment of Occupational Hygiene Standards Part 4 Methods for Determination of Chemical Substances in Workplace Air”, which is suitable for the detection of mifepristone in the air of the workplace.A method to determine acrylic acid in workplace air was developed by on-line methylation gas chromatography. Methods the samples were absorbed by solvent desorption silica gel tube and desorbed by methanol. Desorption fluid in the injector at 350 ℃ in the presence of an organic alkali tetramethylamine hydroxide (TMAH, 25% methanol) , allowed quantitative analysis of acrylic acid as its corresponding methyl derivative by gas chromatography. Results calibration curve of the method was linear within the range 0-258.4 mg/L and showed good linearity with r=0.999 4. The determination limit of the method was 0.9 mg/L, and the minimum detection concentration was 0.06 mg/m(3) (collect 15 L air) . The relative standard deviation (RSD) was 2.2%-2.7% (n=5) . Recoveries were between 96.9-101.6%. Conclusion the results prove on-line methylation gas chromatography is an accurate, simple and high sensitive method for determining acrylic acid in workplace air.Objective To establish a headspace solid phase microextraction-gas chromatography method for determination of n-Butyl alcohol in urine. Methods In October 2019, the n-butyl alcohol in urine was extracted with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) solid-phase microextraction head. The conditions of salt amount, extraction temperature, extraction time and desorption time were optimized. The separation was performed on HP-5 (30 m×0.32 mm×0.25 μm) capillary column and detected with flame ionization detector. The quantification was based on the external standard curve. Results The linear relationship of n-butyl alcohol in urine was good in the range of 0.04-3.00 mg/L, the correlation coefficient was 0.999, the detection limit of the method was 0.04 mg/L, the recovery was 77.4%-102.8%, the intra-run precision was 3.67%-8.11%, and the inter-assay precision was 4.94%-6.90%. Conclusion The method has simple operation, high concentration efficiency and high sensitivity, and it is suitable for the determination of n-butyl alcohol in urine of occupational exposure to n-butyl alcohol.Objective To investigate the clinical manifestations, treatments and prognosis of subacute arsenic poisoning. Methods In January 2020, a retrospective analysis was carried out on 11 patients hospitalized with subacute arsenic poisoning caused by arsenic contaminated drinking water. We observed manifestations, treatments and prognosis. Results The main clinical presentations of subacute arsenic poisoningin were gastroenteritis in early phase, some of them had other organ damage, such as skin, blood, liver, kidney, cardiovascular and so on. The later phase was mainly peripheral nervous system damage. The treatment was mainly to chelate arsenic, protect target organs and treat toxic peripheral neuropathy. Most were significantly recoveried, but the recovery of severe toxic peripheral neuropathy was tardy. Conclusion Acute gastroenteritis is the mainly early manifestation of subacute arsenic poisoning caused by digestive tract, and toxic peripheral neuropathy in the later phase. The prognosis is good, but the recovery of severe toxic peripheral neuropathy is tardy.Objective To explore the feasibility of soft copy image of chest digital radiography (DR(SC)) in pneumoconiosis diagnosis by observing the reading effect of DR(SC) and comparing it with high kV film-screen chest radiography (FSR(HkV)) . To provide a basis for the establishment of a regional information network platform for pneumoconiosis diagnosis. Methods A total of 119 miners who were exposed to silica dust and engaged in copper or lead-zinc mining were collected by the Third People’s Hospital of Yunnan from October 2017 to August 2019. The pulmonary X-ray findings of DRSC and FSR(HkV) in each case were independently judged and diagnosed by three experienced diagnostic physicians, and the final decision was made according to the consensus of most doctors. The consistency of the two imaging methods was analyzed by observing the main small opacity shape, the overall density, the range of distribution, the aggregation of the small opacity and the big opacity, and the diagnosis stage. Results there were 118 males and 1 female with an average age of 46.21 years. Average exposure time 7.38 years. The pulmonary X-ray findings of 113 cases with two imaging methods were mainly the round small opacity of p,q and r,but the reticular irregular opacity were not prominent, Only one case of FSR(HkV) judgment p shape and DR(SC) judgment q shape were observed, The coincidence rate was 99.12% (112/113) . huger opacity were observed in the other 6 cases. The coincidence rate was 95.51% (4/89) between pneumoconiosis-free and stageⅠ, and there was no significant difference between stageⅡand stage Ⅲ (30/30, P>0.05) . Conclusion The x-ray findings of Silicosis with small round shadow in lung can be used by DR(SC) in diagnosis and staging.