Objective To establish an effective method for determination of synthetic cannabinoid JWH-122 by the high-performance liquid chromatography (HPLC), which is controled by China’s Regulations on non-clinical narcotic and psychoactive drug. Methods Methanol-deionized water (50%-50%) was used as mobile phase for gradient elution. In addition to the initial concentration in organic phase, gradient steepness, column temperature, flow rate and other chromatographic conditions, the determine wavelengths were tested so as to ifnd out optimal experimental conditions. Linearity range and speciifcity were tested under optimal conditions, and actual samples were used to verify the method established. Results Under the condition of ultraviolet spectrum detection wavelength at 221nm, initial concentration of 70%, organic phase gradient steepness of 0.5%/min, lfow rate at 1.2 ml/min and column temperature of 30℃,excellent linearity of JWH-122 was observed at 0.002mg/mL-0.1mg/mL and the detection limit (S/N≥3) was 0.1μg/mL. The test of actual samples suggested that JWH-122 was able to be well separated from the sample under the optimal conditions. Conclusion Our method has advantages of rapidity, sensitivity, accuracy and excellent separation efifciency, and is capable of the detection of synthetic cannabinoid JWH-122 of the novel “spice” drugs.

Objective To investigate the use of crime scene investigation umbrellas to solve the problem that it is difficult to show the luminol test for bloodstains in strong light environment.Methods Three objects:red bricks,soil and black cloth were selected,samples with different concentrations of blood and different retention times were,prepared,luminol tests were performed on the same type of samples in a strong light environment,under the umbrella and in a dark room respectively,and photograghic evidence were obtained.Results It was found that bloodstains that could not be directly visualised by luminol test in the strong light environment could achieve better effects in the dark environment formed by the umbrella,and showed unsignificant difference from the results in the dark room.Conclusion Using the umbrella to create a relatively dark environment in strong daylight can easily and quickly perform the luminol test for bloodstains,providing an effective way to discover and extract blood stains in on-site investigations.

Objective To explore the morphological characteristics of overlapping bloodstains and judge the deposition sequence of bloodstain patterns.Methods The overlapping bloodstains formed by drip stains and bloody shoe prints were simulated on ceramic tiles,and the morphological characteristic differences of 6 group overlapping bloodstain patterns were analyzed to screen effective indicative characteristics.A survey was held to measure the accuracy of the participants in judging the blood deposition sequence without and with information about the morphological characteristic guidance.Results After participants mastered morphological characteristics,the accuracy of judging deposition sequence increased from 59.5%to 89.0%,and the accuracy of judging dry and wet conditions of the primary bloodstains increased from 45.6%to 65.3%.Conclusion According to the morphological characteristics of bloodstains,not only the deposition sequence of bloodstains can be effectively judged,but also the dry and wet conditions of bloodstains can be judged,so as to infer the time interval of bloodstains deposition,which can provide technical support for the analysis and reconstruction of crime scene.