Dear Farhana,

Estimation of PHAs by crotonic acid assay:

The amount of PHAs in a sample taken can be determined by spectrophotometric assay. This assay was facilitated by the conversion of PHAs into crotonic acid by sulphuric acid treatment. Crotonic acid standard solution was prepared with different increasing concentrations (10 to 40 µg). Absorbance of crotonic acid was measured at 230 nm and a standard curve was plotted. Then, the sample containing 5 to 50 µg polymer in chloroform was taken in a clean test tube and the solvent was evaporated by heating in a boiling water bath. Then, 10 ml of concentrated H2SO4 was added to the tube and heated for 10 min at 100°C in a water bath. The solution was then cooled and thoroughly mixed. The sample was then transferred to a quartz cuvette and the

absorbance was measured at 230 nm against a sulphuric acid blank. The amount of crotonic acid was then calculated by plotting graph.

For more information on this topic, please see the publications contained in the following links:

http://pelagiaresearchlibrary.com/european-journal-of-experimental-biology/vol1-iss3/EJEB-2011-1-3-180-187.pdf

http://www.academicjournals.org/article/article1404923647_Marjadi%20and%20Dharaiya.pdf

Hoping this will be helpful,

Rafik