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Quality Analysis of Products Related to Health and Safety of Drinking Water in Yantai

Author: ZhangGuiFang
Tutor: Cui
School: Shandong University
Course: Health inspection
Keywords: Water Products Quality Analysis Atomic absorption spectrometry Matrix modifier Immersion test
CLC: R155.5
Type: Master's thesis
Year: 2009
Downloads: 27
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Abstract

Objective: wading products Yantai City within the production and sale of part of the investigation and analysis of samples for laboratory testing. Conventional detection methods to optimize explore a more simple, reliable, lead and cadmium in the determination of the applicable wading flameless atomic absorption spectrometry, and compared with the national standard method. Provide the basis for such products after health and safety and functional evaluation method further standardization administrative department of health policy, strengthen market supervision, to provide the basic data. Method: 1. Study and pretreatment basis: wading detection by immersion test pollutants dissolution and determination of dissolution in order to evaluate the quality of health products, the first step called pretreatment. Wading a wide range of products, the higher frequency of use and is closely related to public life wading representative pipe, pipe fittings, water dispenser and water quality processor as the research object, pipe, tube and water dispenser Pretreatment of drinking water water distribution equipment and protective materials safety evaluation standards prescribed method according to GB / T 17219-1998. The water processor in accordance with the Ministry of Health, \2. Determination of the project: to select the test items. Pipe, pipe fittings, the dispenser three types of product testing lead, cadmium, zinc, iron, total dissolved solids, oxygen consumption, pH, fluoride eight indicators, small water processor detection of lead, cadmium, oxygen consumption, dissolved total solid four indicators. 3 pretreatment and determination of the method optimization: pretreatment method optimization, respectively explore the soaking time, soaking temperature to simulate changes in the circulating water immersion test conditions on the test results. Test methods, determination of lead and cadmium were discussed. (4) the method of quality control: the standard curve, the regression equation and correlation coefficient; calculated the sensitivity and detection limit of the method; precision and accuracy of the actual sample test; 20 independent test results are plotted mean quality control charts to carry out quality control of the sample analysis process. (5) Sampling: 92 samples were collected from Yantai within the city limits wading products manufacturers and operating sales units, including local brands and foreign brands, are inextricably linked to the household daily life wading products. The collected products including the transmission and distribution of water with a plastic pipe, pipe fittings, water dispenser, water quality processor four categories. Results: (1) the determination of lead in Kaki modifier, 2.5 g / L of ammonium dihydrogen phosphate matrix modifier for determination of cadmium, determination is better than the national standard method. The test results during the test always maintain quality control charts controllable range. The GB control sample test results was no significant difference in detection method optimized linear calibration curve was better and a wider range; lower detection limit of lead and cadmium, 1.5ng/ml and 0.2ng/mL respectively; RSD range of 1.13% to 3.82% and 1.67% to 4.88%, significantly better than the national standard method and the difference; recoveries ranged from 95.8% to 102.8% and 96.7% to 102.3%, in line with the requirements. 2 immersion test sample, only when the temperature is changed, the elution amount of the analyte with increasing temperature indicators have different degrees of increase, in the temperature change of 25 ° C to 35 ° C. The elution amount was not obvious, 35 ° C increased to 60 ° C temperature change. If only changing the immersion time, increase the amount of eluted part under test indicators extend over time, 18 to 36 hours of soaking test, U-PVC pipe lead the dissolution amount increase was not significant, the amount of dissolution of zinc in the metal pipe to increase significantly. Temperature limit specified in the national standard can be relaxed to 35 ° C; only plastic pipe lead detection, it can shorten the soaking time to 18h. Analog circulating water and still water immersion test lead test results no significant difference (t = 1.07, P> 0.05). 3 of 92 wading test results show the overall pass rate of 87.0%, including drinking fountains highest pass rate, water quality processor lowest passing rate. From the material conditions, metal products, U-PVC plastic pipe and the quality of the water processor filter material outstanding quality of health problems. From the production units of the sample pass rate was significantly higher than sales units; in Yantai and non Yantai the wading production rate of qualified products were no significant differences; valid health permit this document holds 82.6%, holding a valid health permit this document product testing pass rate was significantly higher than the product without a valid permit this document. Conclusions: 1. Graphite Furnace Atomic Absorption Spectrometry wading products in lead and cadmium, the test of the detection method is superior to the standard method. 2. Immersion test, the time and temperature factors play a key role in the dissolution process of the substance to be measured, the type and effect of the different types of products. Still water immersion test results can represent wading actual use cycle the dissolution effect under the water status. Yantai City, wading quality of the product overall situation is better, but there are still health and safety issues. The questions focused on the sale of units and without a valid health permit this document. Metal products, U-PVC plastic pipe and the quality of the water processor filter material quality of health problems is the main reason affecting the pass rate.

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