Study On Analysis Method Of24Elements In Human Hair And Its Application

The present thesis is intended to establish an inductively coupled plasma-mass spectrometry (ICP-MS) method with microwave digestion as its pretreatment for determination of24elements in human hair, which would provide technical support for developing hair inorganic element database of healthy people and the reference data for forensic investigation of cases, poisoning, the courts and clinical diagnosis and food safety monitoring and the result evaluation. It consists of the following two parts:1.Establishment and application of an ICP-MS method for24elements determinationWith Indium(115In)as an internal standard, a washing method and microwave digestion procedure for hair as well as the operating parameters for inductively coupled plasma mass spectrometry (ICP-MS) was optimized to establish an ICP-MS method for determination of24elements in human hair. Of the6conventional washing ways applied to compare their influence on24elements in the homologous hair to figure out a suitable washing procedure:1%triton X100,5%EDTA,0.1%SLS, washing procedure by IAEA, ultrasound, ultrasound with0.5%triton X-100. ultrasound with0.5%triton X-100is the best choice.Mercury may be absorpted inside the wall of sample bottle or sample introduction of ICP-MS, thus resulting in the loss of mercury and impacting the result. As we know, gold and mercury can form gold amalgam. When gold amalgam is ionized, two elements be separated easily, thus ensuring high efficiency of testing. Mercury concentration was fixed as50μg/L, added respectively different proportion of gold standard solution according to gold mercury ratio ranging20:1,10:1,1:1,1:10,1:20to compare different gold mercury ratio influnce on mercury adsorption. The results indicated that gold mercury ratio between10:1and1:1could reduce the adsorption of mercury.50milligram hair sample could be digested completely in32minutes without residue left inside the bottles of digestion machine by3millilitres65%nitric acid. Mercury recovery was105%~106%, which supportted that the microwave digestion parameters are good for volatile elements.The limits of determination of24elements ranged from0.000μg/g to10.14μ.g/g. all elements within-day precision ranged froml.3%to14.7%, between-day precision ranged from3.4%to12.0%. Human hair certified reference were analysed and excellent agreement with the certified value was abtained for all elements, the recovery of the elements which were not listed in human hair certified reference materials ranged from90%to99%. The method is effective, sensitive, accurate for the determination of24elements in human hair, and suitable for screen test in forensic analysis field, especially for normal heavy mental elements.The established method was successfully used in the judicial authentication practice,2copies hair sample of the poisioner were detected, the thallium content were22.705μg/g,28.367μg/g, the control group content of hair were0.0045,0.013μg/g. Test results show that the case is thallium poisoning.2.Determination of24elements in heroin addictsA statistical analysis of24elements content in hair of56cases of healthy volunteers was made to obtain the normal range.24elements content in hair of23cases of heroin addicts were tested to explore its difference compared to normal range. and10cases whose hair were cut to sections according to the time of withdrawal were studied, to explore the difference before and after treatment in hair by comparing longitudinal different content, to guide the heroin abusers treatment method, to prevent heroin abusers relapses, help the treatments with technology and data support. T test was made between heroin abuses group and control group with Graphpad statistical software, which showed that content of beryllium, gold, barium, cesium, nickel and thorium were extremely significant different (P <0.01), chromium, thallium and uranium were significant different (P<0.05). T test was made between hair sections of the10, testing data shows that the content of magnesium, galliumand barium after treatment was lower than before, statistically speaking, the Study on Analysis Method of24Elements in Human Hair and Its Application Abstract difference is of great significance(P<0.05). Barium may be one of the causes that lead to high-risk arrhythmia and the gastrointestinal tract symptoms for heroin addicters.