LaMotte SMART 2 - Manual (Page 233)

POTASSIUM
TETRAPHENYLBORON METHOD • CODE 3639-SC
QUANTITY CONTENTS CODE
30 mL *Sodium Hydroxide, 1.0N *4004WT-G
5 g *Tetraphenylboron Powder *6364-C
1 Spoon, 0.05 g, plastic 0696
*WARNING: Reagents marked with an * are considered to be potential health
hazards. To view or print a Material Safety Data Sheet (MSDS) for these reagents go to
www.lamotte.com. To obtain a printed copy, contact LaMotte by e-mail, phone or fax.
Potassium, as the seventh most common element on the Earth, may be found
in minor quantities in most water supplies. It seldom exceeds 10 ppm in
drinking water and usually is less than 2 ppm. In some brine or runoff in
agricultural areas the potassium concentration may reach 100 ppm.
APPLICATION: Drinking, surface, and saline water.
RANGE: 0.0–10.0 ppm Potassium
METHOD: Potassium reacts with sodium tetraphenylborate to form a
colloidal white precipitate in quantities proportional to the
potassium concentration.
SAMPLE
HANDLING &
PRESERVATION: Store samples in polyethylene bottles, not in soft glass where
leaching of potassium from the glass may occur. Samples may
be acidified to pH 2 with nitric acid, but should be
neutralized before analyzing.
INTERFERENCE: Calcium and magnesium interfere at very high
concentrations. Check for stray light interference (see p.
17).
Smart2 TEST PROCEDURES 2.04 Potassium 1/2