Detection limit

About: Detection limit is a research topic. Over the lifetime, 34379 publications have been published within this topic receiving 644817 citations. The topic is also known as: limit of detection & lower detection limit.

Electrochemical sensor based on bismuth-film electrode for voltammetric studies on vitamin B2 (riboflavin)

Abstract: Riboflavin (or vitamin B 2 ) was successfully studied by voltammetric techniques and determined in oral, syrup and tablet samples using an ex situ plated bismuth-film electrode (BiFE). Cyclic voltammetry demonstrated that in acetate buffer (pH 4.0) vitamin B 2 undergoes an adsorption-controlled quasi -reversible electron transfer reaction. The peak potentials observed were pH-dependent, involving the same numbers of protons and electrons. The calibration curve provided by square-wave adsorptive stripping voltammetry (SWAdSV) exhibited two slopes: the first ranged from 0.3 to 0.8 μmol L −1 vitamin B 2 and the second from 1.0 to 9.0 μmol L −1 . In the case of the first slope, the detection limit was 100 nmol L −1 and the quantification limit was 300 nmol L −1 . Also, for the measurements, excellent selectivity, repeatability and stability were attained. Fluorescence was employed as the comparative technique and the outstanding performance of the BiFE-SWAdSV for riboflavin determination was verified.

Optimization of methylmercury microwave-assisted extraction from aquatic sediments

Abstract: A simple and rapid method is described for the extraction and determination of methylmercury in marine sediments. The procedure was based on the quantitative microwave-assisted extraction of methylmercury from aquatic sediment samples using hydrochloric acid and toluene as solvents. Two- and three-level factorial designs have been used to optimize the microwave extraction process. Factors such as temperature, hydrochloric acid amount, extraction time, and solvent (toluene) volume were considered. The results suggest that temperature and hydrochloric acid amount are statistically significant factors. The analysis of extracts has been carried out by capillary gas chromatography with electron capture detection.The detection limit of the procedure was 8 ng/g of sediment. Relative standard deviation for the complete procedure was 8%. Validation was carried out against sediment samples submitted to intercomparison studies within the framework of a certification project sponsored by the Bureau of Reference Mater...