It is customary to determine chlorine by the titration with silver nitrate, but it is almost impossible to find out the element in the tissues of organisms or in culture media by this method. The present paper embodies our determination of small amount of chlorine by a nephelometric method, chlorine being measured as silver chloride hereby.
Experiment 1
A varying amount of N/50000 NaCl solution was first acidified with HNO3, 0.2 c.c. of 10% AgNO3 solution was added, and finally distilled water was put to make the mixture 30 c.c. in volume. The chlorine content of this series of the mixtures was determined by a nephelometer in reference to a standard solution which consists of 20 c.c. of N/50000 NaCl solution, 0.2 c.c. of 10% AgNO3, solution, and 3 c.c. of HNO3. It may be mentioned that I c.c. of N/50000 NaCl solution contains 0.0007 mgr. of Cl.
It is clear from the experiment that chlorine was almost exactly determined in the series within the range from 0.008 to 0.018mgr., the experimental error being ±0.001mgr.
Experiment 2
Firstly, 1 c.c. of a broth diluted to ten times was made 100 c.c. in volume with distilled water. Secondly, 1 c.c. of the broth diluted to ten times was mixed with 5 c.c. of N/2000 NaCl solution and then distilled water was added until 100 c.c. Two c.c. and 3 c.c. of each of these two solutions were acidified with HNO3, mixed with 0.2 c.c. of 10% AgNO3 solution, and made 30 c.c. with distilled water. The nephelometric determination of the samples was done with the satisfactory results
