we are developing an impurity method to detect the content of zinc. we found the zinc 66 reading is so high in the blank that even the signals in the standard solutions have no big difference from the blank.
we used water for injection (sterile from BAXTER) to prepare blank and standard solutions.
the questions are:
1. does zinc 66 usually have high counts in water which is not Milli Q?
2. how to reduce Zinc background in blank ?