Quantum dots: a tool for the detection of explosives/nitro derivatives.

Nitro derivatives are considered as major environmental pollutants and issues of health concern. In current times, a variety of methods and techniques have been utilized for the sensing of these nitro derivatives. In view of this, the remarkable fluorescence properties of quantum dots (QDs) provide a great opportunity to detect these nitro derivatives. This review highlighted the recent reports of QDs as the sensing material for these nitro derivative explosives. Different modifications in QDs using physical and chemical approaches can be used to improve their sensing output. Various interaction mechanisms have been discussed between QDs and nitro derivatives to change their fluorescence properties. Finally, the current challenges and the perspective for the forthcoming future are provided in the concluding section. We hope this review will be beneficial in guiding the utilization of QDs in sensing applications.

Development, validation and comparison of two microextraction techniques for the rapid and sensitive determination of pregabalin in urine and pharmaceutical formulations after ethyl chloroformate derivatization followed by gas chromatography-mass spectrometric analysis.

The present article reports first time the use of solid-phase microextraction (SPME) and dispersive liquid-liquid microextraction (DLLME) to extract pregabalin (PRG) from urine and pharmaceutical formulations followed by GC-MS analysis after ethyl chloroformate (ECF) derivatization. PRG is an antiepileptic and analgesic drug, which is a structural analogue of γ-amino-butyric acid (GABA). It is approved by Food and Drug Administration (FDA) for the treatment of central nervous system (CNS) disorders and neuropathic pain. Initially PRG was derivatized with ECF in the presence of pyridine at room temperature for 30s. Experimental parameters were investigated for derivatization, SPME and DLLME conditions. The limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.019 µg/ml and 0.063 µg/ml for SPME and 0.022 µg/ml and 0.075 µg/ml for DLLME respectively. The percentage recovery, in case of SPME was in the range of 83-98% while for DLLME it is in the range of 84-98%. The intra and inter-day precisions were found to be less than 6%. The developed methods after ECF derivatization were found to be simple, fast, efficient and inexpensive. DLLME has several advantages like lesser extraction time and cost effectiveness as compared to SPME. The developed methods may find wide application for the routine determination of PRG in biological as well as in quality control samples of pharmaceutical formulations.