Hitachi ZA3000 Series, Instruction Manual

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3 - 1
3 OPERATION
This chapter describes the operation using the three-liquid flow
channel, in which preliminary reduced sample is measured using
hydrochloric acid and sodium borohydride. For the operation using
the four-liquid flow channel, in which a preliminary reducing agent is
automatically added by the pump, refer to “4 MEASUREMENT
USING FOUR LIQUIDS”.
3.1 Reagents
All reagents should be of analytical grade or higher.
(1) 1% Sodium Borohydride (NaBH
4
) Solution
Dissolve 5 g of sodium borohydride and 2 g of sodium hydroxide
with pure water, and adjust the total volume to 500 mL.
(2) 1.0 mol/L Hydrochloric Acid (HCI)
Dilute 50 mL of hydrochloric acid by adding 550 mL of pure water.
(3) 20% Potassium lodide (Kl) Solution (necessary only for arsenic
measurement)
Dissolve 20 g of potassium iodide in pure water and adjust the
total volume to 100 mL.
(4) 10% Ascorbic Acid (AA) Solution (necessary only for arsenic
measurement)
Dissolve 10 g of L(+)- ascorbic acid in pure water and adjust the
total volume to 100 mL.
(5) Standard Solutions
Dilute a commercially available standard solution (approx.
1,000 mg/L), such as arsenic (As) or selenium (Se).
NOTE 1: When using a toxic, corrosive, or stimulative reagent, be
careful not to incur a physical inflammation or injury.
Reagents should be properly treated by referring to the
SDS (Safety Data Sheet) that provides information about
the material characteristics and handling.
Wear proper protective clothes (e.g. safety goggles and
gloves) so that a reagent will not come into direct contact
with the skin.
Ventilate the laboratory room adequately to prevent
accidental inhalation of harmful vapor.
NOTE 2: Use the sodium borohydride solution only on the day it is
prepared. Do not keep the solution for a longer period
because hydrolysis reaction can occur during storage.