Purified Water Testing (Method of analysis) as per IP/BP/USP

1.0 DESCRIPTION:

A clear, colorless, odorless and tasteless liquid.

2.0 pH:

Take about 100 ml of sample and add 0.5 ml of Saturated KCl Solution and read pH at 25°C on Suitable Calibrated pH Meter.

3.0 CONDUCTIVITY:

Take 100 ml of sample in Closed Bottle and read the conductivity at 20°C on suitably calibrated Conductivity meter.

4.0 ACIDITY OR ALKALINITY:

To 10 ml of freshly boiled and cooled in a borosilicate glass flask, add 0.05 ml of methyl red solution, the resulting solution is not red. To 10 ml add 0.1 ml of bromothymol blue solution, the resulting solution is not blue.

5.0 AMMONIUM:

To 20 ml of sample add 1 ml of alkaline potassium mercuri-iodide solution and allow to stand for 5 minutes. When viewed vertically the solution is not more intensely colored than a solution prepared at the same time by adding 1 ml of alkaline mercuri- iodide solution to a solution containing 4 ml of ammonia standard solution 1 ppm and 16 ml of ammonia free water.

6.0 CALCIUM & MAGNESIUM:

To 100 ml of sample add 2 ml of ammonia buffer pH 10.0 and 50 mg of mordant black II mixture and 0.5 ml of 0.01 M EDTA, a pure blue color is produced.

7.0 HEAVY METALS:

Test solution-Take 12 ml of the solution prepared in the following manner in a glass evaporating dish evaporate 150 ml to 15 ml in a water bath.
Standard solution- Pipette 10 ml of lead standard solution 1 ppm pb.
Procedure- To the cylinder containing the standard solution add 2.0 ml of the test solution and mix. To each of cylinder add 2 ml of the acetate buffer pH 3.5, mix and add 1.2 ml of thioacetamide reagent, allow to stand for 2 minutes and view downwards over a white surface; the color produced with the test solution is not more intense than that produced with the standard solution.

8.0 CHLORIDE:

To 10 ml of sample add 1 ml of 2M nitric acid and 0.2 ml of 0.1 M silver nitrate; the appearance of the solution does not change for at least 15 minutes.

9.0 NITRATE:

To 5 ml of sample in the test tube immersed in ice add 0. 4 ml of a 10 % w/v solution of potassium chloride, 0.1 ml of diphenylamine solution and, drop wise with shaking, 5 ml of sulphuric acid. Transfer to the tube to a water bath at 50° and allow standing for 15 minutes. Any blue color in the solution is not more intense than that in the solution prepared at the same time and in the same manner using a mixture of 4.5 ml of nitrate free water and 0.5 ml of nitrate standard solution 2 ppm NO3.

10.0 SULPHATE:

To 10 ml of sample add 0.1 ml of 2M hydrochloric acid and 0.1 ml of barium chloride solution. The appearance of solution does not change for at least 1 hour.

11.0 OXIDISABLE SUBSTANCES:

To 100 ml of sample add 10 ml of 1M sulphuric acid and 0.1 ml of 0.02 M potassium permanganate solution and boil for 5 minutes; the solution remains faintly pink.

12.0 RESIDUE ON EVAPORATION:

Evaporate 100 ml of sample to dryness on a water-bath and dry to constant weight at 105°C. The residue weight not more than 1 mg (0.001%).
CALCULATION:

         

         Wa-Wb x 100

      ----------------------   =  _______% w/v

               100     

Where-Wa= Wt. of Residue and Beaker

Wb= Wt of empty Beaker

13.0 MICROBIAL LIMIT TEST

TOTAL AEROBIC BACTERIAL COUNT:

Media preparation- Take 40 gm of Soybean Casein Digest Agar medium in 1000 ml volumetric flask and dissolve by gentle heating and make the volume 1000 ml then sterilized for 15 min at 121°C and 15 lbs. pressure.
Procedure- Take six plate and take 0.1 ml in three plats and 1.0 ml for other three plates fill with 25 ml media in each plate leave for cool down then put plate in incubator for 48 hours at 37°C after that count the CFU and calculate the total bacterial count per ml sample.

TOTAL FUNGAL COUNT:

Media preparation- Take 40 gm of Soybean Casein Digest Agar medium in 1000 ml volumetric flask and dissolve by gentle heating and make the volume 1000 ml then sterilized for 15 min at 121°C and 15 lbs pressure.
Procedure- Take six plate and take 0.1 ml in three plats and 1.0 ml for other three plates fill with 25 ml media in each plate leave for cool down then put plate in incubator for 48 hours at 25°C after that count the CFU and calculate the fungal count per ml sample.

Share

Tweet

Share

Share