粉類糧食金屬物的三種測定方法
隨著人們健康意識的提高,對飲食的要求也越來越高,任何影響健康的糧食都將會被“拒之千裏”,就比如最常見的食品加工原料――麵mian粉fen。粉fen類lei糧liang食shi在zai加jia工gong過guo程cheng中zhong可ke能neng會hui產chan生sheng金jin屬shu物wu,如ru果guo長chang期qi食shi用yong這zhe類lei麵mian粉fen,將jiang威wei脅xie到dao人ren體ti健jian康kang。如ru今jin,專zhuan家jia們men會hui根gen據ju全quan國guo糧liang油you標biao準zhun化hua技ji術shu委wei員yuan會hui糧liang食shi及ji製zhi品pin技ji術shu工gong作zuo組zu要yao求qiu,對dui粉fen類lei磁ci性xing金jin屬shu物wu測ce定ding進jin行xing研yan究jiu,探tan討tao出chu了le以yi下xia三san種zhong測ce定ding方fang法fa:
①國家標準對此有嚴格的限製,隻允許粉類磁性金屬物量小於0.003g/kg。目前國內采用GB/T5509―1985方fang法fa檢jian測ce磁ci性xing金jin屬shu物wu雜za質zhi,是shi以yi四si氯lv化hua碳tan作zuo為wei分fen離li磁ci性xing金jin屬shu物wu與yu試shi樣yang混hun合he物wu的de漂piao洗xi溶rong液ye。但dan是shi,四si氯lv化hua碳tan法fa對dui人ren體ti有you毒du害hai作zuo用yong,其qi廢fei棄qi物wu處chu理li不bu當dang還hai會hui汙wu染ran環huan境jing,而er且qie方fang法fa操cao作zuo繁fan瑣suo,不bu易yi掌zhang握wo。
②最常用的是磁鐵法:方法即是:從平均樣品中稱試樣1kg,倒在玻璃板或光滑的平麵台上,攤成長方形,厚度約0.5cm,yongmatixingcitiejiangliangjicharushiyangzhong,citieqianduankelvetigao,houduanyuboliban,jiechu,xiancongshangxiangxiamanmanshunxuyidong,ranhouzaicongzuoxiangyouyidong。dangcitietongguoquanbushiyanghou,yongmaoshuaqingqingshuaqufuzaicitieshangdefeicixingwu,jiangjinshuwushuaruyizhizhongliangdeganguozhong,zaijiangshiyanghunhehou,anshangshufangfajinxingsanci,baxichudecixingjinshuwuyibingchengzhong。zuihoujisuandechujieguo。

③但隨著技術的進步,磁鐵法也逐漸被磁性金屬測定儀這類科學儀器所代替,人們隻需參照使用說明規範操作,都能準確得出測量結果。相比較前兩種測定方法,儀器測定法將更省時、省力,並且還能省下一筆人工成本。



