B. Laassis et al., FLUOROMETRIC-DETERMINATION OF PHENOTHIAZINE-DERIVATIVES BY PHOTOOXIDATION IN A FLOW-INJECTION SYSTEM, Talanta, 41(11), 1994, pp. 1985-1989
Flow-injection analysis (FIA) was combined with photochemically induce
d fluorescence (PF) detection for the determination of four phenothiaz
ine derivatives, including unsubstituted phenothiazine, thionine, Azur
e A and Methylene Blue. The working analytical parameters (flow-rate,
injected volume, photoreactor length) were optimized. Linear calibrati
on graphs were obtained over about two orders of magnitude, with relat
ive standard deviation within the range 1-2.3%. Limits of detection we
re between 13 and 35 ng/ml, according to the compound. The FIA-PF meth
od was applied to the determination of phenothiazines in urine samples
. Mean recoveries ranged from 94 to 117%.