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Total Diet Studies to estimate dietary exposure to food contaminants need to evaluate laboratory measurements data variance. In this process it is critical that data from analytical methods are reliable to correctly scrutinize and compare values over time and between countries. In Europe it is widely recognized that the evaluation of measurement uncertainty is an important parameter when assessing the sources of analytical data variability. Two approaches are considered to estimate uncertainty in analytical measurement. Arsenic, Lead, Chromium and Cadmium, content in several food matrix determined by Inductively Coupled Mass Spectrometry (ICP-MS) microwave digestion assisted, are used as examples. The aim of the present research work is to compare both approaches accepted by Eurolab and GUM: Mathematical modeling to assess uncertainty components based on a classical model (bottom up) and an empirical method (top down), based on either experimental data obtained from a single laboratory validation data or inter-laboratory data from Proficiency Testing schemes. Relative expanded uncertainty calculated by both approaches agree when U (%) <20%. These values are concordant with RSDR reported in collaborative studies of EN 15763 (2009), which were assumed as target uncertainty. The top down approach described is simple and easy to use when compared with the mathematical modeling approach providing considerable benefits to those who assess data produced by several laboratories. 相似文献
14.
In this work were determined triclosan and 4n‐nonylphenol in water from a reservoir that is used to provide water to a purification plant in an important city in Colombia. The analytical methodology was validated using solid‐phase extraction and analysis by gas chromatography‐mass spectrometry (GC‐MS). The analysis by GC‐MS showed good linearity in the range of 0.05–5 μg/L for both compounds. Recoveries from 79 to 109% and standard deviations of 2.5–7.7 for low concentrations and from 3.8 to 9.6 (n = 5) for high concentrations were obtained for both compounds. In Colombia, this is the first time that these compounds have been analysed in water supplying of a drinking water treatment plant. The validated method was applied to the analysis of 27 samples collected in August 2010 in 11 locations from the reservoir and in the influent and effluent of the drinking water treatment plant. In total, seven samples were found to contain triclosan. 相似文献
15.
N. De la Cruz L. Esquius D. Grandjean A. Magnet A. Tungler L.F. de Alencastro C. Pulgarín 《Water research》2013
This study focuses on the removal of 22 selected micropollutants in an effluent from a municipal wastewater treatment plant (MWTP) at pilot scale. A reactor of 37 L with five low pressure mercury lamps emitting at 254 nm (UV254) was used. The 22 micropollutants include 15 pharmaceuticals, 2 X-Ray contrast medias, 1 corrosion inhibitor and 4 biocides/pesticides. Five of these 22 compounds were used as indicative substances as proposed by the Swiss Federal Office for the Environment (FOEN) (carbamazepine, diclofenac, sulfamethoxazole, benzotriazole and mecoprop). 相似文献
16.
Based on the experimental results of the references [1 ] and [2], i.e., the contact re-sistance increases due to the contaminants formed on contact surface with the operating cycles,the physical model and math model of contact failure on small current contacts under mechanicalactions are proposed through deep theoretical analysis in this paper. 相似文献
17.
超声降解技术对废水中的各类有机物具有广泛的适应性,在废水处理中得到了广泛的关注。本文介绍了超声降解的机理和影响因素。超声降解技术和光催化、电催化、化学氧化、生物技术联用可以提高降解有机废水的效率。 相似文献
18.
随着我国经济的高速发展,企业生产的不断扩张,企业的环境突发事故的多变性,对现场监测提出了更高的要求。建立便携式GC-MS,由于其体积小,分析精度高,非常适合于现场挥发性有机物的分析,在国内已被成功用于多起现场环境应急监测工作,本文以一次监测实例说明通过充分利用该仪器快速检测极低浓度挥发性有机污染物的功能,可将之进一步应用于被污染环境空气的实时现场监测,从而为复杂情况下环境污染源的快速排查工作提供强有力的技术支持。 相似文献
19.
《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2013,30(1):9-24
A Total Diet Study (TDS) consists of selecting, collecting and analysing commonly consumed foods to obtain concentration data of different chemical compounds in foods as eaten. A TDS food list summarises the most consumed foods and represents the dietary habits of the general population of the country under study. The work reported here investigated whether TDS food lists that were initially designed for the whole population of the country under study also sufficiently cover the dietary pattern of specific subpopulations that are extra vulnerable for certain contaminants. The work was performed using data of three European countries: the Czech Republic, France and the UK. Each national food consumption database was combined with the corresponding national TDS food list (containing 336, 212 and 119 food items for the Czech Republic, France and the UK, respectively). The data were aggregated on the highest level of hierarchy of FoodEx-1, a pan-European food classification system, including 20 main FoodEx-1 groups. For the group ‘milk and dairy products’, the coverage of the consumption by the food list was investigated for more refined subgroups. For each food group or subgroup and country, the average percentage of coverage of the diet by the national TDS food list was calculated for different subpopulations, including children versus adults, women versus men, vegetarians versus non-vegetarians, and women of child-bearing age versus older women. The average diet of the different subpopulations was sufficiently covered by the food list of the Czech Republic and France. For the UK the average coverage was low due to a different food-coding approach and because food lists were not derived directly from national food consumption data. At the level of the 20 main food groups, differences between the subpopulations with respect to the average coverage of consumption by the TDS food list were minimal. The differences were more pronounced when looking in detail at the coverage of the dairy consumption. TDS food lists based on the mean consumption of the general population are also applicable to study the chemical exposure of different subpopulations, e.g. children, women of child-bearing age and vegetarians. This lowers the effort when performing a TDS. 相似文献
20.
Wenwei Wang Cuijuan Jiang Ledong Zhu Nana Liang Xuejiao Liu Jianbo Jia Chengke Zhang Shumei Zhai Bin Zhang 《International journal of molecular sciences》2014,15(9):15981-15993
Soluble carbon nanotubes (CNTs) have shown promise as materials for adsorption of environmental contaminants such as Bisphenol A (BPA), due to the high adsorption capacity and strong desorption hysteresis of BPA on CNTs. The adsorption of BPA to CNTs may change the properties of both BPA and CNTs, and induce different toxicity to human and living systems from that of BPA and CNTs alone. Herein, we report that oral exposure of BPA/MWCNT–COOH (carboxylated multi-walled carbon nantubes) adduct to mice during gestation and lactation period decreased the male offspring reproductive toxicity compared with those induced by BPA alone. The adduct decreased malondialdehyde (MDA) level in testis and follicle-stimulating hormone (FSH) in serum, but increased the level of serum testosterone in male offspring in comparison to BPA alone. Our investigations broadened the knowledge of nanotoxicity and provided important information on the safe application of CNTs. 相似文献