LaMotte SMART Spectro Spectrophotometer - Manual (Page 231)

APPLICATION: Drinking and surface waters; domestic and industrial
wastewaters.
RANGE: 0.00–3.00 ppm Zinc
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 2/3 SMART SPECTRO TEST PROCEDURES 05.04