horiba TPNA-500, Инструкция по эксплуатации

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Preparation for Operation
34
Preparation of reagent
Note

For preparation, be sure to use pure water (ion-exchange water) with conductivity of 0.05 mS/m
or less.

For measurement of a reagent, be sure to use a calibrated balance with reciprocal sensitivity of
10 mg or less.

Fully understand the property of each reagent before performing the procedure.

The following describes the procedure for preparing 1 L of potassium peroxodisulfate aqueous
solution and 250 mL of another reagent (reagent C: 240 mL). Increase or decrease the amount in
proportion depending on the accuracy of the balance used for measurement and use frequency
of the equipment, etc.

As a reagent cannot be stored for more than one month, prepare it every time you use it. First,
drain the pure water from the tank and replace the residual pure water inside the ion-exchange
water tube completely. Then, replenish the pure water again.
Prepare the following seven reagents.

Potassium peroxodisulfate aqueous solution [Reagent A]

Sodium hydroxide aqueous solution [Reagent B]

Dilute sulfuric acid solution [Reagent C]

L-ascorbic acid aqueous solution [Reagent D]

Mixed reagent [Reagent E]

Hydrochloric acid solution [Reagent F]

Span solution

Consumption of reagents (per measurement)
Application Reagent Concentration
Consum
ption
Reagent
consumption
Reagent A Potassium peroxodisulfate 15 g/L 0.8 mL 0.012 g
Reagent B Sodium hydroxide 40 g/L 0.2 mL 0.008 g
Reagent C Sulfuric acid solution Approx. 4.5 mol/L 0.1 mL 0.025 mL
*1
Reagent D L-ascorbic acid 24 g/L 0.1 mL 0.0024 g
Reagent E
Ammonium molybdate 12 g/L
0.19 mL
0.00228 g
Potassium antimonyl tartrate 0.3 g/L 0.000057 g
Reagent F Hydrochloric acid solution Approx. 1.7 mol/L 0.2 mL 0.029 mL
*2
Span
solution Potassium
dihydrogenphosphate
0.044 g/L 50 mL 0.000044 g
*3
Span
solution
Potassium nitrate 0.361 g/L 50 mL 0.000361 g
*1:
When reagent C (sulfuric acid) is expressed as the capacity ratio, it is approximately
25

(when expressed as the volume ratio, it is approximately 35

).
*2:
When reagent F (hydrochloric acid) is expressed as the capacity ratio, it is approximately
5

(when expressed as the volume ratio, it is approximately 6

).
*3:
For the reagent of span solution, the concentration and consumption vary depending on
the full scale.
Consumption of potassium
dihydrogenphosphate:
For 10 mg/L full scale
Consumption of potassium nitrate: For 50 mg/L full scale