RESUMO
Objective To establish a high performance liquid chromatography (HPLC) through the optimization of the chromatographic conditions, which can detect the contents of clenbuterol hydrochloride (CL) residues in animal edible product in a large quantity. Methods The animal edible product were extracted by perchloric acid, and then impurities were removed by liquid-liquid extraction (LLE) which used ethyl acetate- isopropanol. After the organic phase was concentrated, C18 column (150 mm×4.6 mm, 5 μm) was used to separate CL. Mobile phase were methanol-sodium dihydrogen phosphate, and then determined by HPLC. Results A good linear response was obtained over the range of 0.2-10.0 μg/mL with the correlation coefficient (r) 0.99984. The method determination limit was 0.15 μg/kg which was lower than the National standard method 0.5μg/kg. The retention time of the CL was 6.51 min, the chromatographic peak was good. The recovery rates spiked with standards 1.6-12 μg were 92.86％-100.93％, which was higher than National standard method (89.79％-92.36％) . The precision of intra-day and inter-day were both under 5％, which lower than National standard. Conclusion The optimized chromatographic conditions are suitable for the large quantity determination of clenbuterol hydrochloride in animal edible product.
RESUMO
Objective To master the prevalence status of schistosomiasis in Yunnan Province in 2016,so as to provide the evidence for formulating the control strategy and intervention measures. Methods The schistosomiasis heavy-endemic villages were selected from each of 18 endemic counties as the survey sites. Then,the serological and etiological tests were carried out in the local residents and floating population,and the infection status of the livestock,field feces and Oncomelania hupensis snails were surveyed. Results The serum positive rate of schistosomiasis of local residents was 8.78％and the serum positive rate was 2.26％of floating population. No schistosome eggs were found in the stool examinations in the population. The area with snails was 80.0546 hm2 in 2016 with an increasing rate of 45.47％compared to that in 2015. The average density of living snails was 0.0317/0.1 m2. No schistosome-infected snails were found for the last four years and no new area with snails was found for the last three years. No positive livestock or feces were found. Conclusions The schistosomiasis epidemic situation is stabilized in Yunnan Province in 2016. However,the area with snails and the number of living snails are increasing,and therefore,the schis-tosomiasis epidemic risk still exists. So,the comprehensive control measures should be strengthened continuously.
RESUMO
Objective To investigate the effect on radioactivity in drinking water around Qinshan nuclear power station (QNPS)in normal operational condition.Methods The field monitoring and laboratory analysis methods were adopted to detect the total radioactivity level in drinking water in 2015,according to different distances from the nuclear island and different types of water.Results The total alpha and total beta radioactivity level in drinking water around QNPS were 0.027(0.098)Bq /L and 0.263(0.071)Bq /L respectively,which were obviously lower than the national health standard limits(total alpha and total beta are 0.5,1.0 Bq /L respectively).Total radioactivity level had no relation with the distance from the nuclear island (P >0.05).The total alpha radioactivity in deep well water was the highest among the investigated three types of drinking water,and the highest value was 0.224 Bq /L.The beta radioactivity level in river water was the highest,and the highest value was 0.408 Bq /L.The total alpha radioactivity level was 0.017 (0.013)Bq /L in 2015, higher than the average level during 2010—2014.The beta radioactivity average level was 0.319 (0.102)and 0.289 (0.055)Bq /L,also higher than the average level during 2010—2014.Conclusion The total radioactivity in drinking water among nuclear power plant is in normal background level,so at present there is no effect of the radioactive contamination on drinking water around QNPS in nuclear power plant's normal operational condition.