Analysis And Determination Of Toxic Elements In Packaging Materials

The large quantity and variety of packaging materials used make these matrices a potential source of pollutants that may enter the environment during the utilization process. Contents of toxic elements in packaging materials have a close bearing on human health and national stability and development and are important reflection of packaging safety.According to the ECD irective94/62/EC regulating the concentration of in plastic packaging and packaging materials, the content of chromium, cadmium, lead and mercury should not exceed100μg/g. The EN-71-3and ASTM F963-2003regulate the maximum levels of lead (Pb), mercury (Hg), arsenic (As), cadmium (Cd), chromium (Cr), selenium (Se), antimony (Sb) and barium (Ba) in toy.Presently, analysis of packaging materials at home and abroad mainly concentrated in the study of dioxin, residual solvent, pest, colony count and decorating design. But for the toxic elements, there are few reports on the determination of above eight elements simultaneously. There is a variety of ways to determine toxic elements in packaging materials. For example:Polarography, Spectrophotometry, Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-OES), Atomic Absorption Spectrometry (AAS), Atomic Fluorescence Spectrometry (AFS), and Inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS has now become an acknowledged powerful technique for the measurement of trace element and isotope owing to its wide linear dynamic rang, low limit of detection, high sensitivity, simple lines, rapid analysis, smulti-element capability selectively.To study the toxic elements in packaging materials is an important topic in modern packaging industry. Because of the harm of heavy metals to human health, it is important to accurately determine toxic elements in packaging materials. The content of trace elements is low, so the analytical method for the determination of trace elements in packaging materials should be sensitive and selective. More and more attention have been paid to ICP-MS method owing to its remarkable advantages. In this work, Pb, Hg, As, Cd, Cr, Se, Sb and Ba in kinds of packaging materials were accurately determined by ICP-MS after microwave digestion. The pretreatment conditions of samples such as the effects of digestion media, the selection of internal standard elements and the interference of the method were comprehensively investigated, and the optium conditions for the determination were tested and discussed. The results show that the contents of these elements in kinds of packaging materials have significant difference. This work provides some basic dates for quality control of the packaging materials.The safety condition was introduced for the source and harm of harmful elements in import and export packaging materials in chapter1. The limit rules of harmful heavy metal elements in various packaging materials and the progress of harmful elements analysis in our country were analyzed.A method was developed for determination of Pb, Hg, As, Cd, Cr, Se, Sb and Ba in paper and wood Packaging materials by ICP-MS in chapter2. The microwave digestion factor was choiced on proportion of acids, digestion system, digestion order and instruments parameters of ICP-MS, which offer reference on the preparation of samples alike. The detection limits for8elements were between0.03μg/L and0.21μg/LA method was established for the analysis of harmful elements in plastic packaging materials by microwave digestion-ICP-MS in chapter3. This paper studies the preliminary treatment by analyzing polyethylene, polyvinyl chloride. The digestion system, digestion temperature, and digestion procedures were optimized which offer reference on the prerapation of polymers alike. Method detection limits were very low. The recoveries of all sample elements were between85.6%～104.1%.A method was presented for the analysis of Pb, Hg, As, Cd, Cr, Se, Sb and Ba in metal packaging materials by ICP-MS in chapter4. The acid system and proportion of acids, and whether it needs to microwave digestion or not were discussed detailed, import system and stability testing for ICP-MS have been optimized, meanwhile, the method was modified by adding internal standard elements to eliminate matrix effects and signal drift because of the complex composition of metal packaging.