[Photoionization ion mobility spectrometry (UV-IMS) for the isomeric volatile organic compounds].

The construction and performance study is reported for a newly developed ultraviolet photoionization ion mobility spectrometry (UV-IMS). In the present paper, an UV-IMS technique was firstly developed to detect eleven isomeric volatile organic compounds including the differences in the structure of carbon chain, the style of function group and the position of function group. Their reduced mobility values were determined and increased in this order: linears < branches < cycles, primary < secondary < tertiary, para- < meta- < ortho- and alcohols < acetones < aromas. The concentrations of analytes were obtained by means of exponential dilution method, and the experiments show that the limit of detection of the homemade UV-IMS was around ppb-ppm.

[Rapid detection of residual cyclohexanone in disposable medical devices by ultraviolet photoionization ion mobility spectrometry (UV-IMS)].

In the manufacture of disposable PVC medical devices, cyclohexanone is frequently used as an adhesive reagent, which can be released into the tube airspace or stored solution and thus may cause some adverse effects on patients in therapy. In this paper, an ultraviolet photoionization ion mobility spectrometry (UV-IMS) technique has been developed to detect cyclohexanone through monitoring the gas composition within a package of infusion sets. The concentrations of cyclohexanone were prepared by means of exponential dilution method, and the experiments show that the UV-IMS has a limit of detection at 15 ppb and its measurable linear dynamics range is over three orders of magnitude. The concentrations of cyclohexanone in three brands of infusion sets packages were determined to be 16.78, 17.59 and 46.69 ppm respectively. The UV-IMS is proposed as a tool for the quality control of medical devices to monitor illegal uses of chemical solvents like cyclohexanone.

[Survey on prevalence of 1 526 children with sleep disturbances in age of 2 to 12 years old in Chengdu].

OBJECTIVE: To find out the prevalence of sleep disturbances for children aged 2 to 12 years old in Chengdu. METHODS: Totally 1 600 children aged 2-12 years old were selected from 5 districts in Chengdu and investigated by using questionnaire. RESULTS: All 1 526 survey papers were returned. The average time of every day sleep in each age group (infant group, pre-school age group and school age group) were 12.12 hours, 10.42 hours and 9.47 hours. The sleep time of the children in those three groups were much less than the standard one. The proportion of the prevalence of sleep disturbance was 37.88%. Among them, there were snoring in 5.57%, choke/gargling in 1.25%, sleep inquietude in 7.86%, mouth breathing in 4.59%, sweating in 21.36%, member spasm in 2.82%, molar teeth in 8.26%, night talking in 4.02%, somnambulate in 0.2%, bedwetting in 1.95%, and difficulty falling asleep in 10.75%. There were significant differences shown in different sexes and ages, and in incidence of symptoms of some sleep disturbances. The affecting factors were the co-sleeping, tonsillitis, bronchitis, pollen allergy and their parent's snore. CONCLUSION: The prevalence of sleep disturbances being higher and more severe than before might be due to the less sleeping time in Chengdu in children aged 2 to 12 years old. More attention should be paid by parents, the Ministry of Education and the children's doctors.