Designed experiment teaching fits well with characteristic of naval hygiene training subjects on the sea.Attention should be paid to several key points including content selection,training plan design and teaching effect evaluation.It was proved that designed experiments enhanced the practical ability of the undergraduates and significantly improved the effect of naval hygiene training subjects.

Objective The method for the analysis of Methylenedioxypyrovalerone (MDPV) in urine by liquid-phase small-extraction- GC/MS have been developed and studied . Methods A 1-mL of urine sample was adjusted to pH9 with sodium bicarbonate, and was extracted with 50μL dichloromethane. The mixture centrifuged at 14000g for 2 min . A 1-μL organic phase was injected into the GC/MS system. Results The calibration curves showed good linearity in range of 0.05μg/mL~0.20μg/mL , and the limit of detection was 0.02μg/mL, and the RSD was 3.86~5.69%, and the recovery rate was 86.5~92.8 %. Conclusion The method is sensitive, accurate and was easy to operate for fast detection of MDPV in human urine.