Question

Ion chromatography - Anions lab

Transfrer quantitatively the weighed portion of NaCl to the 100-ml volumetric flask. The flask need not be dry but must have been rinsed with de-ionied water as described above. why?

Transfer approximatrly 1.5 times the volume of ACPS that you will need to a small beaker that will be supplied by instructor. This beaker will already have been rinsed with ACPS. Why should you not put your pipet directly into the bottle of ACPS solution that is used by other students?

Answer 1

Solution.

Natural and tap water contain chloride-ions, which will interfere the ion chromatography analysis. Deionized water contains no Cl^- ions, therefore, it should be used. The volumetric flask need not to be dry because it will be eventually filled with water up to a 100 mL mark.

If every student will put his pipette to a bottle with ACPS solution, it may be polluted, diluted by a water from a dirty pipette and so on. As it is a primary standard solution it should be kept with extreme precautions, otherwise, its concentration and purity will drift.