Determination Of Trace Arsenic And Mercury In Food Additives By Hydride Generation-Atomic Fluorescence Spectrometry

Arsenic and compounds of arsenic have high biotoxicity.Trivalent arsenic could cause toxicosis of cells and capillary vessel through long-term exposure,even place a premium on therioma.Arsenic is one of the most important elements for detection in food additives.There are five methods for arsenic detection at present,silver diethyl-dithiocarbamate method,method of spot of As,hydride generation-atomic fluorescence spectrometry and borohydride reduction colorimetric method.The usual chemical methods are silver diethyl-dithiocarbamate method and method of spot of As.The silver diethyl-dithiocarbamate method takes a lot of trouble in operator. Method of spot of As is a method of semi-quantitative analysis.Both methods are low sensitivity and low accuracy.Mercury and mercury compound are widespread and large reserves heavy metal element in nature.Mercury and mercury compound polluted air, water and soil by being expelled in environment,which result in pollution of food.The toxicity of mercury has relationship with their existing form and integral absorbed dose of mercury compound.Inorganic mercury compound are not easy being absorbed,so their toxicities are weak.On the contrary,the toxicities of organic mercury compound are strong,especially mercury alkyl.The detecting methods of mercury are cold vapor atomic absorption spectrometry and hydride generation atomic florescence spectrophotometry.Food additives are important constitutes on modern food industry. They have important functions on food qualities improving,nutrition increasing and prevent food from decay et al.The national standards for arsenic detection in food additives are silver diethyl-dithiocarbamate method and method of spot of As(GB/T5009.76-2003;GB/T 8450-1987).We have no national standard for mercury detection in food additives at present.As a special analysis way,Atomic fluorescence spectrometry has the virtues of atomic emission and atomic absorption method.It was a new technique that could combine hydride generation technique and atomic fluorescence spectrometry method together.The technique has high sensitivity and low interferent and has superiority to the detection of As and HgObjectiveThis research mainly from how to simplify a sample processing,make certain the best instrument conditions,make certain the concentration of the medium and KBH₄,applied even design and confirm accuracy and precision of the method,discuss the possibility of hydride generation atomic fluorescence spectrophotometry to be used on measures of the arsenic and mercury in food additives.Discuss the possibility of hydride generation atomic fluorescence spectrophotometry to be used for which measures the arsenic and mercury in food additives synchronously.Methods1.The pretreatment of the sample.The article studied the pretreatments of several kinds of food additive and found simple method to deal with samples.2.According to experimental principia of the methods for detecting As and Hg,we ascertain action system and the best instrumental conditions. 3.Compare the detecting results of the method with the other methods.4.To validate the accuracy and precision of the method and calculate the detection limit.Results1.The article studied the method for detecting As and Hg in food additives by hydride generation-atomic fluorescence spectrometry, found the pretreatment of the samples for suppressing interference.2.We established the method of detecting As and Hg in frequently-used food additive by hydride generation-atomic fluorescence spectrometry. The method was applied to detecting the samples and the outcome was satisfied.3.The recovery rate of As and Hg were 88.1%～108.8%and 90.7%～100.4%, the relative standard deviation were 0.48%～2.57%and 1.88%～3.31%,the detection limits were 0.51ng/ml and 0.15ng/ml.ConclusionAccording to experiments of laboratory,we established the method for detecting As and Hg in food additives by hydride generation-atomic fluorescence spectrometry.It was indicated by investigation results that the method was simplicity of operator,exact,quickly and easy to be spread.The method was suitable for grass roots laboratories.