ASTM E534 – 13 Chemical Analysis of Sodium Chloride

Scope:

Sodium chloride is a naturally occurring substance. It is a vital component of the human diet as well as a source of various salt compounds and chlorine. ASTM E534 – 13 test method explains how to analyze sodium chloride to see if it’s acceptable for its intended usage. 

Procedure:

ASTM E534 – 13 test method two aliquots of the stock solution is pipetted into 400-mL beakers, yielding a titer of 2–10 mL standard EDTA solution. This solution is then placed on a magnetic stirrer after diluting to 200 mL with water. 5 mL buffer solution, 1 mL KCN solution, and enough Eriochrome Black T Indicator Solution is added to get a real blue hue, titrated using a typical EDTA solution and recorded the milliliters as T1. In the case of calcium to precipitate magnesium, 2 mL of KOH solution is added and 1 mL of KCN solution to the other aliquot and mixed for about 2 minutes then nough murexide solution (or an analogous calcium indicator solution) is added to the mixture. To get a real blue hue, titrated using a typical EDTA solution and recorded the milliliters as T2. 

Specimen size:

100 g sample is used for ASTM E534 – 13 test method and must be conditioned at 110°C for one hour.

Data:

Mass percent of calcium in ASTM E534 – 13 test method is calculated as:
Ca, % mass (m/m) = (T2) (factor) (0:1)/S
Where:
T2 = EDTA used to titrate calcium only
S = mass of salt in aliquot, g
Mass percent of magnesium is calculated as:
Mg, % mass (m/m) = (T1 ̶ T2) (factor) (0.6064) (0.1)/S
Where:
T1 = EDTA used to titrate total calcium and magnesium.
S = mass of salt in aliquot, g