Determination of Unsymmetrical Dimethylhydrazine in Soil by Gas Chromatography-Mass Spectrometry with the Pretreatment of Alkaline Distillation and Ultrasonic Derivatization / 分析化学

An analytical method was developed for the determination of unsymmetrical dimethylhydrazine ( UDMH ) in soil samples by gas chromatography-mass spectrometry with the pretreatment of alkaline distillation and ultrasonic derivatization. After pretreated by the alkaline distillation, the quantitative analysis of UDMH was conducted in selected ion monitoring ( SIM ) mode by using salicylaldehyde as derivatization reagent and ultrasonic to accelerate the derivative reaction. The characteristic ion of the derivative product named salicylaldehyde dimethylhydrazone was m/z 164 . Impact factors including types of the alkaline distillation and the derivative conditions with ultrasonic were investigated. The conditions of derivatization were optimized. Under the optimal conditions, linear range of the method was 0. 4-30 mg/L. The limit of detection (LOD, S/N=3) was 0. 0078 mg/kg. The method was used to detect total UDMH in real soil samples with known concentration. The recoveries ranged from 76% to 108% with relative standard deviations ( RSD) of 12%-19% at different spiked concentration levels from 10 mg/kg to 100 mg/kg. In comparison with the methods of spectrophotometry and Soxhlet extraction-ultrasonic derivatization, this method had lower detection limit, and could be used to detect total UDMH in soil samples.

Effect of radix salviae miliorrhizae on acute lung injury caused by inhalation of rocket liquid propellant / 中华急诊医学杂志

Objective To investigate the effect and mechanisms of radix salviae miliorrhizae (RSM)on acute lung injury (ALI)caused by inhalation of high concentration rocket liquid propellant unsymmetrical dimethylhydrazine (UDMH)and dinitrogen tetroxide (N_2O_4). Methods Forty-two rats were divided into three groups:the control group,the inhalation group and the inhalation plus treatment group (RSM group).The latter two groups were inhaled with UDMH 0.98 g/m3 for ten minutes and N_2O_4 0.19 g/m3 for ten minutes.After the inhalation,the rats in RSM group were treated with 9 g?kg -1 RSM intravenously immediately,and were injected into peritoneal cavity with RSM at a dose of 3 g?kg -1 at the 3 hours after the first injection.The rats in other group were treated with equivalent saline.All rats were killed after the observation for six hours.Lung wet to dry ratio (W/D),LDH and total protein in bronchoalveolar lavage fluid (BALF),the activities of superoxide dismutase (SOD)and glutathione peroxidase (GSH-Px)in lung tissue,and the malondialdehyde (MDA)of plasma were measured.Histopathology was observed.Results The lung W/D ratio,LDH and total protein in BALF,MDA of plasma were increased in the inhalation group,while the activities of SOD and GSH-Px in lung tissue were decreased.The histopathology of the inhalation groups rats showed that exudation within alveolar space and interstitial thicken of septa was prominent.In the RSM group,above index were improved,and the degree of lung injury in histopathology was relieved.The lung W/D were related to the activities of SOD and GSH-Px in lung tissue,correlation coefficient were-0.661(P