Drug Delivery & Targeting (Track)

Determination of Nitrite and Nitrate in Food and Drug with Spectrophotometric Detection by FIA

Asghar Kazemzadeh
Materials & Energy Research center P.O.Box 14155 - 4777 Tehran - IRAN

Abstract:

The direct spectrophotometric method for the simutaneous detertermination of nitrite and nitrate by flow-injection analysis has been developed.The method is based on the reaction of nitrite with safranine O to form a diazonium salt which caused the reddish-orange dye colour of the solution to be changed to blue in acidic media, and hence decreasing the absorbance of system at 520 nm. The injected sample in the flow-injection system is split in two segments. One of them is transported through a reductor minicolumn containing copperised cadmium, in which the reduction of nitrate to nitrite occurs, and then the total nitrite concentration,i.e initially plus produced, was determined as described. The ifluence of reagents concentrations and manifold parameters were studied. The effect of potentially interfering ions were examined and procedures for elimination of interfering cations are proposed. Nitrite and Nitrate can be determined for the range of 0.0001 -3.00mg.ml-1 and 0.005 -3.40 mg.ml-1, respectively, with a sampling rate of 20 + 3 h-1. The detection limits of 0.0005mg.ml-1 and 0.003 mg.ml-1 were obtained for nitrite and nitrate, respectively. Nitrite and nitrate were determined in food and drug samples by the proposed method with satisfactory results.

Keywords: Nitrite, Nitrate , Spectrophotometry Detection, FIA