本修改单经国家标准化管理委员会于2009年3月24日批准,自2009年7月1日起实施。GB 12593-2008《工作基准试剂乙二胺四乙酸二钠》国家标准中修改内容如下:第5.3.1条款第四行中的“称量乙二胺四乙酸二钠标准滴定溶液,应精确至0.0001g。”修改为:“称量氯化锌标准滴定溶液,应精确至 This revised form approved by the National Standardization Management Committee March 24, 2009, since July 1, 2009 come into operation. GB 12593-2008 “working reference reagent disodium edetate,” the contents of the amendment as follows: Article 5.3.1 of the fourth line in the “weighing ethylenediaminetetraacetic acid standard titration solution should be accurate to 0.0001g. ”Amend to read as follows:" Weighing standard solution of zinc chloride should be accurate to