Determination of ATP via the photochemical generation of hydrogen peroxide using flow injection luminol chemiluminescence detection.

The determination of ATP using the coupling between a photochemical reaction and a chemiluminescence reaction in a flow injection (FI) system is described. The method is based on the reaction of glucose with ATP catalyzed by hexokinase and Mg(2+) ions. The glucose that is not consumed by ATP is subsequently photooxidized using 9,10-anthraquinone-2,6-disulfonate as a sensitizer. The hydrogen peroxide produced in the photochemical reaction is monitored through the chemiluminescence reaction with luminol catalyzed by hematine. There is a linear relationship between the decrease in the chemiluminescence response and the ATP concentration at a constant concentration of glucose. Under the optimum conditions, the calibration graph is linear in the range 0.20-50.5 mg L(-1) with a throughput of 25 samples per hour and relative standard deviations between +/-0.62 and +/-1.42%. The limit of detection is 0.07 mg L(-1). The method was used for the determination of ATP in pharmaceuticals, milk, and soils.