LaMotte SMART3 Colorimeter - Manual (Page 290)

APPLICATION: Drinking and surface waters, domestic and industrial
waste water.
RANGE: 0.00–3.00 ppm Zinc
MDL: 0.05 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 CrO4(II) 50
Fe (II) 9
ZINC, Low Range SMART3 Test Procedures 11.11
Test P
rocedures