(来学网)为测定水样中氰化物,水样采集后应加入某种物质使pH达到定的要求,并于4℃℃保存。加入的物质和pH的要求分别是
  • A.
    (来学网)NaOH,使pH>10
  • B.
    (来学网)HN03,使pH<2
  • C.
    (来学网)H2SO4,使pH<2
  • D.
    (来学网)NaOH,使pH>12
  • E.
    (来学网)醋酸锌