A flow injection chemiluminescence method for determination of nalidixic acid based on KMnO4–morin sensitized with CdS quantum dots

• Characterization of synthesized CdS QDs by XRD, SEM and PL
• Nalidixic acid determination using KMnO4–morin sensitized with CdS flow CL
• Determination of nalidixic acid in real samples
• Comparison of CL method with corona discharge ionization ion mobility spectrometry

A simple and sensitive flow injection chemiluminescence (CL) method was developed for determination of nalidixic acid by application of CdS quantum dots (QDs) in KMnO4–morin CL system in acidic medium. Optical and structural features of l-cysteine capped CdS quantum dots which were synthesized via hydrothermal approach were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), and ultraviolet–visible (UV–Vis) spectroscopy. Moreover, the potential mechanism of the proposed CL method was described using the results of the kinetic curves of CL systems, the spectra of CL, PL and UV–Vis analyses. The CL intensity of the KMnO4–morin–CdS QDs system was considerably increased in the presence of nalidixic acid. Under the optimum condition, the enhanced CL intensity was linearly proportional to the concentration of nalidixic acid in the range of 0.0013 to 21.0 mg L− 1, with a detection limit of (3σ) 0.003 mg L− 1. Also, the proposed CL method was utilized for determination of nalidixic acid in environmental water samples, and commercial pharmaceutical formulation to approve its applicability. Furthermore, corona discharge ionization ion mobility spectrometry (CD-IMS) method was utilized for determination of nalidixic acid and the results of real sample analysis by two proposed methods were compared. Comparison the analytical features of these methods represented that the proposed CL method is preferable to CD-IMS method for determination of nalidixic acid due to its high sensitivity and precision.

The intensity of emitted light from KMnO4–morin–CdS QDs system is described as a sensitive chemiluminescence (CL) reaction. The CL intensity of this CL system is remarkably enhanced in the presence of nalidixic acid.Figure optionsDownload as PowerPoint slide