A method was developed for the determination of four sulfa antibiotics in groundwater, soil and excreta using solid phase micro extraction disks coupled with high performance liquid chromatography. The influence of eluent, different solid phase micro extraction membranes on the recovery of sulfa antibiotics in groundwater was investigated and it was found that when using the mixture of methyl alcohol and 1 . 0% formic acid as eluent, HLB ( divinyl benzene-N-vinyl pyrrolidone polymer ) as extraction membranes, an optimal enrichment effect was obtained. Different pretreatment methods for the 3 kinds of samples abovementioned were also examined. It was found that the signal response values obtained by using mixture of methyl alcohol and 1 . 0% formic acid as base solution of standard or sample solution was higher 8-10 times than that by using methyl alcohol only. Under the optimal conditions, good linear relationships were obtained in the sulfa antibiotics concentrations of 0 . 005-10 . 0 mg/L with the correlation coefficients>0 . 9999;The detection limits of sulfathiazole ( ST ) , sulfadiazine ( SM ) , sulfamethazine ( SM2 ) , sulfamethoxazole ( SMX ) were 1 . 08 , 3. 56, 4. 63 and 1. 84 ng/L(S/N=3), respectively. The enrichment factors for four sulfa antibiotics were 4000 times with solid phase micro extraction disks. The RSD of matrix spiked samples were 0. 1%-0. 4%(n=7). The proposed method was applied to the determination of the four sulfa antibiotics in groundwater, soil and excreta with spiked recoveries of the four sulfa antibiotics in the range of 69 . 80%-117 . 60%.

Objective This study aims to investigate the moral disgust cognitive processing of patients with obses?sive-compulsive disorder (OCD) and its relationship with OCD symptoms. Methods Twenty-eight OCD and 30 healthy controls matched for gender, age and education completed lexical decision task, recording reaction time and accuracy of words and assessing the degree of disgust. Yale-Brown obsessive-compulsive scale (Y-BOCS) and Padua Invento?ry-Washington State University Revision (PI-WUSR) were used to assess the symptoms. Results OCD group showed significantly longer reaction time to core disgust-related words [(762.69 ± 128.25) ms vs. (648.69 ± 162.66) ms] and moral disgust-related words [(798.73 ± 115.26) ms vs. (727.00 ± 106.06) ms] than the healthy controls (P<0.05). OCD group showed significantly higher aversion degree to core disgust-related words [(6.38 ± 1.78) vs. (5.03 ± 1.64)] and moral dis?gust-related words [(7.08 ± 1.23) vs. (5.77 ± 1.44)] than control group (P<0.05). Y-BOCS total score, Y-BOCS obsessive thoughts score, Y-BOCS compulsive behavior score, total score of PI-WUSR, cleaning/pollution force factor score, hurt?ing themselves and others force factor were positively correlated with two types of disgust-related words in patients group (P<0.05). Multiple stepwise regression analysis between disgust words and Y-BOCS/PI-WUSR scores pointed that only CWCF influenced disgust degree of core disgust-related words (β=0.61, P<0.01) and moral disgust-related words (β=0.54, P<0.01), respectively. Conclusion The core disgust and moral disgust of OCD are stronger compared to controls.