[Investigation on endemic situation of schistosomiasis in infection-controlled regions in Anhui Province].

OBJECTIVE: To understand the epidemic situation of schistosomiasis in 27 counties (cities, districts) that reached the criteria of schistosomiasis infection controlled in Anhui Province. METHODS: According to the requirement of The National Assessment Scheme of Schistosomiasis, 81 administrative villages where the schistosomiasis epidemic situation was relatively heaver in above-mentioned 27 counties (1 village per town, 3 towns per county) were sampled and investigated. RESULTS: From 2012 to 2014, 81 villages were investigated, and 34,293 residents received the serum examinations, and 1,086 were positive with a positive rate of 3.17% (0.65%-9.58%), and the positives received stool examinations and the average stool positive rate was 0.37% (0-4.0%). The calculated prevalence of human infection was 0.01%. A total of 3 057 domestic animals were investigated including 438 cattle, 2,550 sheep, and 69 other animals, and no infections were detected. A total of 11,261 living Oncomelania hupensis snails were collected and detected, but no schistosome infected snails were found. Before this investigation, no infected snails were detected for more than 2 years [average 2.3 (2-6) years], and no acute schistosome infection cases were found for more than 2 years [average 4.9 (2-9) years]. CONCLUSION: The infection rates of schistosomiasis in residents and domestic animals are relatively low, and no schistosome infected snails are found in the regions.

[Comparison of pretreatment methods for the simultaneous determination of diclazuril and toltrazuril residues in chicken tissues].

The effects of four pretreatment methods (acetonitrile extraction-evaporation concentration, acetonitrile extraction-solid phase extraction (SPE), matrix solid-phase dispersion (MSPD) extraction and MSPD-SPE) for the simultaneous analysis of diclazuril and toltrazuril residues in chicken tissues were compared. The average recovery of 70% for the former three methods as achieved. In comparison with other methods, the MSPD method saved more than 60% in time and solvent. So, MSPD as the sample pretreatment method, an MSPD-high performance liquid chromatography with ultraviolet detection (MSPD-HPLC/UV) method was established for the analysis. Under the optimal chromatographic conditions, the linear range was between 50 and 1,000 microg/kg. At the added levels of 50, 500, 1,000 ng/g, the recoveries of diclazuril and toltrazuril in chicken tissues ranged from 71.13% - 84.02% with the relative standard deviations (RSD) in the range of 3.76% - 12.11%, and the RSDs of intra- and interday analyses ranged from 3.70% - 6.77%. The detection limits of diclazuril and toltrazuril were less than 10 microg/kg. The quantitative limits of diclazuril and toltrazuril were less than 20 microg/kg. The method meet the requirements of the residue analysis on accuracy and precision.

[Simultaneous determination of residues of three fluoroquinolones in chicken using high performance liquid chromatography with post-column derivatization and terbium sensitized fluorescence].

A method of high performance liquid chromatography with post-column derivatization and terbium sensitized fluorescence for simultaneous determination of residues of ciprofloxacin, norfloxacin and enrofloxacin in chicken was established, based on the effect that Tb3+ can sensibilize fluorescence of fluoroquinolones. Under the optimal chromatographic condition, three fluoroquinolones were separated on a C18 column with 0.05 mol/L acetic acid/acetate buffer-acetonitrile (89:11, v/v) as the mobile phase, and at a flow rate of 0.8 mL/min; then were derivatized with 8 x 10(-5) mol/L Tb3+ at 40 degrees C, and at a flow rate of 0.5 mL/min; finally were detected using a fluorescence detector (lamda(ex) = 271 nm, lamda(em) = 545 nm). The recoveries of three fluoroquinolones ranged from 66.3%-88.0% at the added levels of 1.0, 10.0, 50.0, and 100.0 ng/g, and the relative standard deviations (RSDs) were less than 15.0%. The linear range for quantitative analysis was between 0.1 and 500 ng/mL. All the RSDs of the inter-day and intra-day analyses were less than 13.0%. The detection limits were 0.05 ng/g for ciprofloxacin and norfloxacin and 0.08 ng/g for enrofloxacin. The method is sensitive for the determination of multi-residues of fluoroquinolones in chicken.