The Improvement of EDTA Titration Method in Zn Testing of oft-com:office:smarttags" />
///In the testing of Zn content, the recovery can be 98. 2~104. 6%, RSD(n=12) 0.12~3.57%. According to the examination of standard sample and outer comparison, the testing result is reliable, stable and satisfactory. oft-com:office:office" />