have been trained to use laboratory practices which are considered safe and prudent by chemical industry standards. Such practices include suitable personal protective equipment, the use of proper equipment, the use of proper methods of handling all chemicals and proper laboratory procedures. Use only analytical reagent grade chemicals and deionizedordistilled water in the following analytical procedures. 以下分析程序建议由经过化学工业标准认为安全谨慎的实验室操作培训的人员使用。这些做法包括适当