Study On Speciation Analysis Of Heavy Metals In Tobacco

Heavy metals are defined as the metals whose density is greater than5. The deficiency or excess of most heavy metals will do harm to human health. Tobacco can enrich heavy metals from soil, air and water. When a cigarette is smoked, the toxic heavy metal is inhaled into the human body with cigarette smoke and may cause cancers. With the rising tide of the global anti-smoking campaign and the implementation of Framework Convention on Tobacco Control (FCTC), the quality safety of tobacco products has aroused widespread concern, and the heavy metals in tobacco have become one of the focuses. Heavy metals in tobacco could be divided into different species, such as insoluble, soluble, inorganic, organic, different valence and combination states. Heavy metals of different species have different effects on human body, some useful, some harmful, some greatly toxic and some slightly toxic. In addition, heavy metals of different species have different physical and chemical properties, their migration characteristics in cigarette smoke must be different. Some heavy metal can easily migrate to smoke while others can’t. So, in order to evalute the harmfulness of heavy metals in tobacco, we should not only consider the total content of heavy metals, but also the contents of different species and their migration characteristics in cigarette smoke. Now most studies focus on the determination of total amount of heavy metals in tobacco leaves and cigarette smoke, few studies about the speciation analysis of heavy metals in tobacco have been reported. So, it is important and far-reaching significant to strengthen in-depth study of separation and determination of heavy metals of different species in tobacco in order to understand comprehensively heavy metals of tobacco and its products, evaluate objectively hazards of heavy metals in tobacco, monitor their contents in tobacco and its products, reduce the risks of smoking and keep the sustainable development of tobacco industry.The separation technology of heavy metals of different species in tobacco has been systematically studied, and the separation method of six heavy metals in tobacco has been established. The optimal separation conditions of insoluble and soluble, inorganic and organic states were determined. The contents of total and different species heavy metals in tobacco leaves planted in Anhui and the contents of heavy metals in the corresponding unblended cigarette mainstream smoke have been determined. The research results can be briefed as follows:1Through the study of separation technology of insoluble and soluble heavy metals in tobacco, the separation method of Cr, Ni, As, Se, Cd, Pb in tobacco has been established. The optimal conditions were ultrapure water and50min centrifugation time. The relative standard deviation of this method was from0.1%to4.5%. The results showed that the separation method is accurate and reliable, and can be effectively used to separate insoluble and soluble Cr, Ni, As, Se, Cd, Pb in tobacco.2Through the study of separation technology of inorganic and organic heavy metals in tobacco, the separation method of Cr, As, Se, Cd in tobacco has been established. The optimal conditions were AB-8macroporous resin,10.0cm resin height, pH3.0,1.0%HNO3solution concentration and70.0%ethanol solution concentration. The relative standard deviation of this method was from0.3%to4.0%. The recovery of inorganic cadmium was from93.1%to101.3%. The results showed that the separation method is accurate and reliable, and can be effectively used to separate inorganic and organic Cr, As, Se, Cd in tobacco.3The total contents of heavy metals and contents of heavy metals of different species in36tobacco leave samples planted in Anhui were determined according to the standard method (YC/T380-2010) and the above mentioned separation methods. The contents of heavy metals in the corresponding unblended cigarette mainstream smoke were determined according to the standard method (YC/T379-2010).4The detection results of the heavy metal contents of the tobacco leaves and the corresponding unblended cigarette mainstream smoke have been analyzed by simple correlation analysis. The relationship between the contents of some heavy metals in unblended cigarette mainstream smoke and the corresponding contents of total, different species heavy metals in tobacco has also been obtained.