An Improved Lindemann Method for Colorimetric Determination of Inorganic Phosphate in Biological Samples

Centre for Add Zone Studies, U. C. N. W., Bangor, Gwynedd LL57 2UW, Wales, United Kingdom

Manuscript received 21 April 1986, revised 3 September 1987, accepted 13 January 1988

THE Fiske- Subbarow method¹ for the quantitative determination of inorganic phosphate suffers from the lack of stability of the blue colour of the reduced phosphomolybdate complex. The method was modified by Lindemann² using a combination of hydrazine sulphate and stannous chloride, by Martland and Robison³ using quinols in sodium sulphate and by Ames⁵ using ascorbic acid as the reductant. Further modifications were carried out by Delory⁴ and King⁵ , and the latter has been successfully used by Khan and Rao⁶.