The Methodology Of Lead Detection And Lead Survey In Stationery For Painting And Writing

Objective:To understand the lead contamination in the stationery for painting and writing and prepare materials for inspection policies in the future. Method:( I ) The detected part of stationery was soaked in 0. 07mol/ L hydrochloric acid to lixiviate soluble lead with vibration immersion and heat immersion respectively .The total lead and soluble lead were detected with Flame Atomic Absorption Spectroscopy(FAAS) and Graphite Furnace Atomic Absorption Spectroscopy (GFAAS). (II) Different kinds of stationery for painting and writing were sampled from 2 main wholesale markets,3 department stores and 5 stationers in Guangzhou. Some samples,such as crayon and pencil,were treated with traditional vibration immersion and heat immersion respectively to lixiviate soluble lead before examined with GFAAS and FAAS. The results were evaluated by the Safety of Toys which qualify samples by less than 250mg/kg soluble lead. Results:( I ) Heat immersion had 98.9-103% callback rates for soluble lead and its RSD less than 8.3%. Compared to vibration immersion,heat immersion shortened detection hour,increased efficiency and yielded more correct results,thus suitable to examine large sums of samples. In this research,FAAS had a least limit of 0.03ug /ml and precision of 0.1% for lead while GFAAS had a least limit of 0.03ug /ml and precision of 0.1%. Though both the callback rates of two methods met the detection conditions,GFAAS yielded rapidly and correctly.(II) 9 brands of crayons with 116 breeds were examined. 5 samples in 2brands had high leads,concluding a rate of 4.31%. The highest was 17 times of the standard. 3 brand watercolors with 30 breeds were examined. 11 samples had high leads,concluding a rate of 36.67%. The highest was 19 times of the standards. 12 colors of advertising paintings were examined. 2 colors had high leads and the highest was lemon (37050mg/kg,148 times of the standard). 12 colors of powdered watercolor were examined and the leads in all samples met the standard. 9 kinds of pencils from different factories were examined. 6 samples had high leads,concluding a rate of 66.67%. The highest was 17 times of the standard. Besides,53 kinds of toy mud and 4 other toys were examined. All these samples contained very low leads and met the standards. Conclusions:( I )During detecting lead in stationery and toys,Heat immersion was better than vibration immersion by shortening detection hour,increasing efficiency and having more correct results. GFAAS operated more simply and yielded more correctly than FAAS. ( II) lead contamination in stationery for painting and writing was existent. To prevent children from lead poisoning and promote health,some measures should be taken to reduce the lead in these kinds of stationery...