LaMotte SMART Spectro Spectrophotometer - Manual (Page 257)

APPLICATION: Drinking and surface waters; domestic and industrial
wastewaters.
RANGE: 0.00–3.00 ppm Zinc
MDL: 0.025 ppm
METHOD: Zinc forms a blue colored complex with Zincon in a
solution buffered at pH 9.0. Other heavy metals are
complexed by cyanide and the zinc cyanide complex
is released by the addition of formaldehyde before the
other metal cyanide complexes are destroyed. Sodium
ascorbate is added to reduce the interference of
manganese.
SAMPLE HANDLING
& PRESERVATION:
Sample should be analyzed within 6 hours after
collection. The addition of hydrochloric acid will help
preserve the metal ion content, however the acid should
be neutralized before analysis.
INTERFERENCES:
The following ions interfere in
concentrations greater than those listed.
ION MG/L
ION MG/L
Cd(II) 1 Cr(III) 10
Al (III) 5 Ni(II) 20
Mn (II) 5 Co (II) 30
Fe (III) 7 CrO
4
(II) 50
Fe (II) 9
ZINC SMART Spectro Test Procedures 2.11
Test P
rocedures