牛奶是人体所需营养成份较好来源之一,各品牌的塑瓶装纯牛奶在本市销量较大,但偶然发现有的纯牛奶瓶底有棕黑色沉淀物,为了解有沉淀的纯牛奶的卫生状况,我们在对纯牛奶进行卫生指标检测的同时,对金属含量进行了分析,现将测定结果报告如下.1 材料与方法1.1 样品来源 有沉淀物的纯牛奶为厂家提供,纯牛奶对照样从市场采集.1.2 样品预处理 将有沉淀物的纯牛奶静置过夜后,上清液轻轻倒入一容器中,获得上层液,将留下的约15ml牛奶及沉淀物混匀,获得下层液.取对照纯牛奶及经处理的上、下层液各10ml,按GB/T5009.12一1996食品中铅测定方法中湿式消解法消化后,定容至50ml,供测定用.1.3 测定条件 日立180-80原子吸收分光光度计,空气-乙炔火焰原子吸收分光光度法,各元素测定条件参照仪器设定测定条件,火焰雾化器用国产高效雾化器改装.2 结果 Milk is one of the better sources of nutrients needed by the human body, the brand of bottled pure milk sold in the city larger, but occasionally found some pure brown milk bottle with a dark precipitate, in order to understand the precipitation of pure milk Health status, we carry out the health indicators of pure milk testing at the same time, the metal content were analyzed, the determination results are reported as follows.1 Materials and methods 1.1 Sample sources Pure milk with sediment for the manufacturers to provide, pure milk control Collected from the market.1.2 Sample Pretreatment After the pure milk with the precipitate was allowed to stand overnight, the supernatant was gently poured into a container to obtain the supernatant, and the remaining about 15ml of milk and the precipitate were mixed to obtain the lower layer Liquid. Take control milk and untreated upper and lower 10ml each 10ml, according to GB / T5009.12 a 1996 Determination of lead in food after digestion by wet digestion, constant volume to 50ml, for measurement purposes .1.3 Determination of Hitachi 180-80 atomic absorption spectrophotometer, air - acetylene flame atomic absorption spectrophotometry, the determination of the elements with reference to the instrument set the measurement conditions, the flame atomizer with domestic efficient nebulizer modified.2 results