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A simple and rapid sample preparation method of dispersive liquid-liquid microextraction(DLLME) was applied in the simultaneous determination of six parabens in the aqueous cosmetics. The analysis was performed on gas chromatography coupled with a flame ionization detection(GC-FID). The mixed solution containing 30 μL of chloroform(extraction solvent) and 300 μL of tetrahydrofuran(dispersive solvent) was rapidly injected into the sample solution for the purpose of microextraction. After that, the solution mentioned above was centrifuged at 4000 r/min for 10 min, and then the organic sediment phase was detected by GC-FID. The effects of experimental parameters, such as the extraction solvent and the volume of it, and the dispersive solvent and the volume of it, on the yield of the extraction were studied in detail. Under the optimum conditions, the enrichment factors of the target analytes range from 87 to 214. Linearity ranges are 0.05–10.0 μg/mL for methylparaben and 0.025–5.0 μg/mL for the other five parabens. The relative standard deviations(RSDs) are lower than 8.2%(n=6). The proposed method was applied to the analysis of six parabens in eleven aqueous cosmetics. The recoveries of the target analytes in the spiked real samples are in the range of 81.0%–103%.

Background Accelerated population ageing brings about unprecedented challenges to the health system in China. This study aimed to measure the prevalence and the income-related inequality of depressive symptoms, and also identify the determinants of depressive symptom inequality among the elderly in China. Methods Data were drawn from the second wave of the China Health and Retirement Longitudinal Study (CHARLS). Depressive symptoms were assessed with a 10-item Center for Epidemiologic Studies–Depression Scale (CES-D), which was preselected in CHARLS. The concentration index was used to measure the magnitude of income-related inequality in depressive symptoms. A decomposition analysis, based on the logit model, was employed to quantify the contribution of each determinant to total inequality. Results More than 32.55% of the elderly in China had depressive symptoms. Women had a higher prevalence of depressive symptoms than men. The overall concentration index of depressive symptoms was -0.0645 among the elderly, indicating that depressive symptoms are more concentrated among the elderly who lived in economically disadvantaged situations, favoring the rich. Income was found to have the largest percentage of contribution to overall inequality, followed by residents’ location and educational attainment. Conclusion The prevalence of depressive symptoms in the elderly was considerably high in China. There was also a pro-rich inequality in depressive symptoms amongst elderly Chinese. It is suggested that some form of policy and intervention strategies, such as establishing the urban-rural integrated medical insurance scheme, enhancing the medical assistance system, and promoting health education programs, is required to alleviate inequitable distribution of depressive symptoms. Electronic supplementary material The online version of this article (doi:10.1186/s12889-016-3876-1) contains supplementary material, which is available to authorized users.

Hydrodistillation (HD) coupled with headspace single-drop microextraction by using ionic liquid (IL) as the extraction solvent, followed by gas chromatography analysis technique, was successfully developed to determine the volatile and semivolatile compounds in seeds of Cuminum cyminum L. In the proposed method, a 1.5-μL microdrop of 1-octyl-3-methylimidazolium hexafluorophosphate, working as the extraction solvent was suspended in the headspace of a 50-mL round-bottom sample flask. After extracting for 30 min, both IL and target analytes were injected into the gas chromatographic system by thermal desorption for 5 s under 240 °C. Then, the IL was retracted back to the microsyringe. Thus, the capillary column should not be contaminated and a clean chromatogram was obtained. The parameters affecting extraction performance were investigated and optimized. The extraction efficiency of the proposed method was compared with that of HD, which is a standard extraction method. The contents of constituents in the extract obtained by the proposed method were close to those obtained by HD. It seems to be an environmentally friendly, time-saving, high efficiency and low solvent consumption technique and would be useful, especially for aromatic plants analysis.

Background Policy interventions have been taken to protect households from facing unpredictable economic changes that may cause catastrophe in China. This study aims to estimate the change of overall proportion of households incurring catastrophic health care expenditure (CHE) and its income-related inequality in the rural areas of Shaanxi Province from 2008 to 2013. Methods The data were drawn from the National Household Health Service Surveys of Shaanxi Province conducted in the years 2008 and 2013. In total, 3,217 households in 2008 and 13,085 households in 2013 were selected for analysis. A “Capacity to pay” approach was used to measure the incidence of CHE. The concentration index was employed to measure the extent of income-related inequality in CHE. A decomposition method, based on a logit model, was used to decompose the concentration index into its determining components. Results From 2008 to 2013, the overall proportion of households incurring CHE dropped from 17.19 % to 15.83 %, while conversely, the inequality in facing CHE strongly increased. The majority of observed inequalities in CHE were explained by household economic status and household size in 2013. In addition, the absence of commercial health insurance and having elderly members were also important contributors to inequality in CHE. Conclusions Even though we used a conservative method to measure CHE, the overall proportion of households incurring CHE in Shaanxi Province is still considerably high in both years. Furthermore, there exists a strong pro-rich inequality of CHE in rural areas of Shaanxi Province. Our study suggests that narrowing the gap of household economic status, improving the anti-risk capability of small scale households, establishing prepayment mechanisms in health insurance, strengthening the depth of reimbursement and subsidising vulnerable households in Shaanxi Province are helpful for both reducing the probability of incurring CHE and the pro-rich inequality in CHE.