The Determination Of Copper(â…¡) By Test Paper

Environmental pollution by heavy metal copper and its compounds,can’t break down, but it can in under the action of microorganisms can be converted into more toxic metal compounds. The content of copper in water is0.01mg/L to inhibit the water self-purification. Copper content in the water to3mg/L, produce peculiar smell;For more than15mg/L, cannot drink. So,it is of great significance to inspect the content of heavy metal copper in he water fast and accurately.At present,there are a lot of ways to detect copper (Ⅱ),such as spectrophotometry, chromatography, electrochemical method,chemical luminescence,capillary method,test paper, in which the most commonly used way is spectrophotometry.In order to find out one way of low-cost, fast, accurate and simple in operation to inspect nitrite, this study will make comments on five ways including bicyclohexanone oxalyldihydrazone spectrophotometry,1-(2-pyridylazo)-2-naphthol spectrophotometry,spectrophotometric chromazurol S,Cu-crystal violet-thiocyanate spectrophotometric method,diethyl dithiocarbamate spectrophotometry.By comparing the minimum detection limit of these five ways,finally I have come to the conclusion that sulfanilic amide-X spectrophotometry was the best way.After studying the chromogenesis between and heavy copper,a new method was proposed for the rapid-determining trace heavy copper in water. The result showed as follows:Based on the sensitive and selective reaction of Cu2+and biscyclohexanone oxaldihydrazone (BCO) in basic solution,a simple,sensitive and low cost method was developed for the determination of trace copper in water. In the research, all chemicals and the effects of reaction temperature and foreign ions have been studied in detail. At the optimum test conditions, the reaction of Cu2+and BCO in basic media proceeds rapidly at room temperature without additional caloric.And the linearity equation is A=0.1052×(Cu2+,mg/L)-0.0018,r2=0.9999.The relative standard deviation(RSD) calculated from20times repeated determine is0.94～2.96%(Cu2+).The detection limit (IUPAC) is0.008mg/L.The parameters of the proposed method were comparable with current national standard methods for the determination of copper in water samples.In the absence of some pretreatment process,such as concentration and separation,the proposed method could test directly copper at trace level in water.This study is managed to establish a test strip way to detect copper in water, and make comments on the way of test strip. And the linearity equation is y=-118.56x+1148.1(R2=0.9880)(0<x<5mg/L);y=-35.829x+761.05(R2=0.9932)(x≥5mg/L).The relative standard deviation (RSD) calculated from20times repeated determine is5.00～10.00%(Cu2+);The detection limit (IUPAC) is0.32mg/L;the recovery rate is between93.09-102.05%.Tests picked the most suitable method of detected sample,the results are water sample can be detected directly. And test strip used in the determination of copper tea.Tests picked the most suitable method of detected sample,the results are tea sample can be after wet digestion alkaline pH to be measured again. Comparing the way of detecting copper in sample, atomic absorption spectrometry (determination of copper in foods GB first method),no significant difference was found.The test strip has the advantages of fast detection, high sensitivity,simple operation cooperated with photoelectric detection apparatus made by ourselves. Putting the reflection value of light as the indicator, the content of copper could be detected according to the color variation of the test strip.