Study On Analysis Method Of34Elements In Human Hair And Its Application

The present thesis is intended to establish an inductively coupled plasma massspectrometry （ICP-MS） method with electric heating board digestion as its pretreatmentfor the determination of34elements in human hair and the washing method of the hair.The determined elements include essential trace elements of human such as iron zincselenium cobalt manganese chromium molybdenum and nickel, and harmful elementsendangering human health such as lead mercury arsenicn and cadmium. Establishmentof analysis method would provide technical support for developing the database ofinorganic elements in healthy people’s hair, and scientific evidence for forensicinvestigations, poisoning case investigation, trial in court, and clinical diagnosis. Itconsists of the three following parts:1. Establishing an ICP-MS method for the determination of34inorganicelements in the hair.ICP-MS method was established for the determination of34inorganic elementsin the hair. Lithium（⁶Li）, Germanium(⁷²Ge), Yttrium(⁸⁹Y), Indium(¹¹⁵In), andTerbium(¹⁵⁹Tb) were used as internal standard, electric heating board digestion wasselected to be used as the pre-treatment of the hair.Owing to the different background levels of elements in the hair and responds ofdifferent elements, the limits of determination of34elements in hair ranged from0.0001μg/g to10.92μg/g. The scope of the recovery is86%¹13%. The inter-dayprecisions of all elements ranged from0.4%to8.9%, intra-day precisions ranged from1.1%to9.2%. These results demonstrated that the established method is fast, effective,sensitive and accurate for determining34elements in human hair. It is suitable foranalysis of large quantities of samples.2. Investigation of the hair washing methodThis section examines washing effect of six conventional washing approaches onunexposed hair and exposed hair. Six conventional washing reagents were compared: 0.1%SDS,1%EDTA,1%triton X-100,0.1mol/L HCl,0.1mol/L NaOH and acetone.According to washing on unexposed hair, we could draw the following conclusions:（1） compared with the rest of the washing reagents, washing effect of triton X-100andIAEA are worse, so they are discarded.（2） SDS, EDTA, HCl and NaOH have significantwashing effect on some elements （3） Most of external contamination can be eluted by0.1mol/L hydrochloride acid.According to washing on exposed hair, determined elements could be split intofour groups.Group A contain Li, Mg, Al, Ca, Zn, Rb, Sr and Sn. The results suggest that theseelements can not adsorbed to the surface of the hair, external contamination of theseelements were almost completely removed in the washing, hence, it is possible todistinguish between endogenously elements and external contamination for theseelements.Group B contain B, Ti, V, Mn, Cu, Ga, As, Se, Mo, Cs, Ba, Hg, Pb and U. Theresults suggest that these elements could adsorbed to the surface of the hair, but externalcontamination of these elements were almost completely removed when washed withsuitable washing procedures, hence, it is possible to distinguish between endogenouslyelements and external contamination of these elements.Group C contain Be, Cr, Fe, Co, Ni, Zr, Cd and Tl. The results suggest that if theseelements adsorbed to the surface of the hair, these elements could not be fully removedwhen washed with any washing procedures investigated, hence, it is not possible todistinguish between endogenously elements and external contamination of theseelements.Group D contain Ag, Sb, Au and Th. The results suggest that if these elementsadsorbed to the surface of the hair, these elements could be hardly removed whenwashed with any washing procedures investigated, hence, it is not possible todistinguish between endogenously elements and external contamination of theseelements.According to washing on exposed hair, we could draw the followingconclusions:（1） by carrying out suitable washing procedures it may now be possible todifferentiate between endogenously elements and external contamination of theseelements of group A and B. Compared with concentration determined in unwashed hair,measured value of elements of group C was close to its true value when the hair were washed by carrying out suitable washing procedures. It would be of no benefit to washhair samples in a pre-treatment step when determining these elements of group D（2）Eluting capacity of1%SDS and1%EDTA are worse than0.1mol/L HCl and0.1mol/LNaOH for washing of exposed hair.In summary, we could draw the following conclusions,（1）0.1mol/L hydrochlorideacid could be used as washing reagent for unexposed hair, the step of washing isproceeding as table7（2） According to determined elements,0.1mol/L hydrochlorideacid or0.1mol/L sodium hydroxide could be used as washing reagent for exposed hair，the step of washing is proceeding as table7.3. Comparison of elements contents in the hair between healthy volunteersand methamphetamine addictsA statistical analysis of34elements contented in the hair of58healthy volunteerswas made to obtain the normal range. Afterwards,34elements contented in the hair of76methamphetamine addicts were tested to explore the difference between addictsgroup and control group. Rank sum test was made between methamphetamine abusersgroup and control group with SPSS statistical software, which showed that the contentsof magnesium, aluminium, calcium, vanadium, rubidium, strontium molybdenumcadmium lead and uranium were significantly different （P <0.01） between two groups,as well as boron, iron and cobalt （P <0.05）. Magnesium and vanadium may be one ofthe causes that lead to high-risk arrhythmia of methamphetamine addicts.