检测水样中"三氮",在采样前应在采样容器中加入的水质保存剂是
A H<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0.gif">SO<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0_1.gif"> B
Na<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0_2.gif">CO<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0_3.gif"> C
NaHCO<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0_4.gif"> D
Na<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0_5.gif">SO<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12475434_0_6.gif"> E
NaCl