CdS nanoparticles‐ enhanced chemiluminescence and determination of baicalin in pharmaceutical preparations

Abstract

CdS nanoparticles (CdS NPs) of different sizes were synthesized by the citrate reduction method. It was found that CdS NPs could enhance the chemiluminescence (CL) of the luminol-potassium ferricyanide system and baicalin could inhibit CdS NPs-enhanced luminol-potassium ferricyanide CL signals in alkaline solution. Based on this inhibition, a flow-injection CL method was established for determination of baicalin in pharmaceutical preparations and human urine samples. Under optimized conditions, the linear range for determination of baicalin was 5.0 x 10(-6) to 1.0 x 10(-3) g/L. The detection limit at a signal-to-noise ratio of 3 was 1.7 x 10(-6) g/L. CL spectra, UV-visible spectra and transmission electron microscopy (TEM) were used to investigate the CL mechanism. The method described is simple, selective and obviates the need of extensive sample pretreatment.

Flow‐injection chemiluminescence method to detect a β2 adrenergic agonist

“…Moreover, the absorption intensities of λ 302 and λ 420 for K 3 Fe(CN) 6 were obviously decreased. It could be demonstrated that the light emitter of the CL system was the excited state of 3‐aminophthalhydrazide, which was in agreement with reports that the luminant of potassium ferricyanide with luminol was considered to be the excited state of 3‐aminophthalhydrazide ; the light emission emanating from relaxation of the excited state of 3‐aminophthalhydrazide then returned to ground state. Terbutaline sulfate could be oxidized by K 3 Fe(CN) 6 , and during this process produced active oxygen‐containing reactant intermediates, such as superoxide radical (·O 2 − ).…”