Objective: To establish a solvent desorption gas chromatographic method for determination of Sevoflurane, Isoflurane and Enflurane in the air of the Workplace. Methods: Sevoflurane, Isoflurane and Enflurane were collected with activated carbon tube and desorbed with dichloromethane, separated with DB-1 capillary columns, and then detected with flame ionization detector. Results: The linearity ranges were 1.9-304.8 μg/ml for Sevoflurane, 2.1-300.4 μg/ml for Isoflurane and 1.7-305.2 μg/ml for Enflurane, The correlation coefficient was both >0.999. Their limits of detection were 0.6 μg/ml, 0.6 μg/ml and 0.5 μg/ml, and Their limits of quatification were 1.9 μg/ml, 2.1 μg/ml and 1.7 μg/ml, and their minimum detectable concentrations were 0.1、0.2 and 0.1 mg/m³ per 4.5 L of air. Their relative standard deviations (RSD) were 2.5%-3.0%, 2.3%-3.1% and 2.2%-3.0%. The average desorption efficiencies were 101.1%-103.3%, 100.7%-102.7% and 101.0%-102.9%. The sampling efficiency was both 100%. The breakthrough volume of 100 mg actived carbon was 3.7 mg, 3.4 mg and 3.4 mg. Sevoflurane, Isoflurane and Enflurane in activated carbon tube could be kept at least 10 days at room temperature without significant losses. Conclusion The method shows lower detection limit, high accuracy and precision. It is feasible for determination of Sevoflurane, Isoflurane and Enflurane in the air of workplace.

Objective:To explore the traits of functional connectivity of resting-state networks in patients of schizophrenia with auditory verbal hallucinations (AVH) by using independent component analysis (ICA).Methods:All patients were met the Diagnostic and Statistical Mannal of Mental Disorders,Fourth Edition,Text Revision (DSM-IV-TR) diagnostic criteria for schizophrenia.Thirty schizophrenia patients with frequent AVH (AVH),24 schizophrenia patients without AVH (non-AVH) and 60 healthy controls (HC) matching with age and gender were analyzed by resting functional magnetic resonance imaging.The AVH were assessed by using Hoffman auditory hallucination scale.By using ICA,auditory network (AUN),language network (LAN),salience network (SAN),right front-parietal network (RFP) and default mode network (DMN) were selected as interesting networks for further analyses.Covariance analysis was used to compare the activity and functional connectivity of multiple resting state networks between three groups,and correlation analysis was used to evaluate the relations between abnormalities of brain and the severity of hallucination.Results:Compared to non-AVH,AVH group showed increased activity in left superior temporal gyrus (STG) and left postcentral gyrus (LPG) in the AUN,and showed decreased activity in right anterior cingulate cortex (ACC) in the SAN (P ＜ 0.05,FDR corrected).The severity of AVH group was associated with activity of the left STG (r =0.43,P ＜0.05) and the right ACC (r =-0.48,P ＜0.01).Furthermore,compared to non-AVH group,there were decreased connectivity between LAN and AUN [(-0.29 ±0.21) vs.(-0.16 ± 0.17),P ＜ 0.05,uncorrected],decreased connectivity between SAN and LAN [(-0.09 ± 0.22) vs.(-0.06 ± 0.18),P ＜ 0.05,uncorrected],increased connectivity between SAN and AUN [(0.30 ± 0.18) vs.(0.15 ± 0.24),P ＜ 0.05,uncorrected] in AVH group.Conclusion:There may be aberrant functional connectivities of AUN,LAN and SAN in schizophrenia patients with frequent AVH,and the occurrence of AVH seems to be related to brain areas involved in language production,speech perception and self-monitoring.