Abstract: A simple and rapid method was described for determining determining content by differentiall pulse polarography .The digest was diluted and pipetted into a solution of formaldehyde in an acetate buffer.The hexamethylentetramine,produced by ammonia and formaldehyde reaction was determined electrochemically at-0.9V .The coefficicient of variation was 4.6% to 5.2%,.The recovery rate of nitrogen was 94.5% to 103.1%.Human milk and eleven different food-stuffs were analysed.There was no significant difference between the results by this method and K jeldahl method.

Key words: Differential pulse polarography, Protein, Nitrogen, Food-stuff kjeldahl method