Determination of pH value of Aqueous Extracts of Textile Materials

 

pH-meter


pH value of Aqueous Extracts of Textile Materials


APPARATUS 

  • Conical Flask with stopper- 250 ml (Chemically resistant glass)
  • Beaker-250ml (Chemically resistant glass)
  • Balance-accurate to 0.05 g
  • Buffer solution pH 4 & 9.2
  • Mechanical shaker 30 RPM
  • Distilled water (pH- 6.5- 7.0) and conductivity 2X10-6 S/cm at 27±2°C

  •  pH METER (Graduated in 0.1 unit of pH)  

 

PEOCEDURE 

  • Condition the sample to moisture equilibrium in standard atmosphere temperature 27±2 °C and HR 65± 2 %.
  • In cold method, prepare the extract in triplicate at lab temperature.
  • Take sample 2g ± 0.05 g add 100 ml distilled water in conical flask close with stopper.
  • Agitate the flask for 20-30min by hand (Ensure wetted out) and shake mechanically for 30min.
  • Wash the electrode, take first extract, immerse the electrode for 3 min. Read the pH.
  • Drain the cell and pour in new portion of the same extract.
  • Allow the cell stand for 1 min. read the pH. Repeat these operations until pH is steady value.
  • Without washing out the cell allow for 2nd extract read the pH (Follow point 7)
  • Determine pH of third extract with above procedure (see point 7 & 8)  
  • PH of 2nd extract & 3rd extract are duplicates.


pH-meter-calibration


Calibration of pH Meter

Wash the electrode with distilled water.

  •        Allow the pH 7.0. Read the pH.

Wash the electrode with distilled water.

  •        Allow the pH 4.0. Read the pH.

Wash the electrode with distilled water.

  • Allow the pH 9.2. Read the pH.


The pH value nearest 0.1 units


INDEX OF DIFFERENCE:

If the pH is less than 3.0 and more than 9. Take 10ml extract in100 ml volumetric flask make up with distilled water.


Measure the pH to 0.1 unit (It should be never greater than unity)


REFFERENCE SPECIFICATION     :     IS 1390-1983


Post a Comment

0 Comments