James K. Kearns

Bio: James K. Kearns is an academic researcher from Southern Connecticut State University. The author has contributed to research in topics: Silver nitrate. The author has an hindex of 1, co-authored 2 publications receiving 4 citations.

Expanding Quantification of Arsenic in Water to 0 μg L−1 with a Field Test Kit: Substituting 0.4% M/V Silver Nitrate as the Colorimetric Reagent; Employing Digital Image Analysis

Abstract: This study confronts the questionable reliability and accuracy of field test kits distributed globally to determine arsenic in drinking water. Because kits are the primary method of arsenic analysis in the areas most affected, an alternate, nontoxic formulation is needed to provide accurate results. Hypothesizing that introducing silver nitrate as the reagent in test kits could successfully substitute for restricted mercuric bromide, the study found that the reformulated kits provided reliable, precise, and accurate results over a broader range of contamination. Digital image analysis was used to examine the blue color value produced when arsine reacts with silver nitrate impregnated test strips. An optimal concentration of AgNO3 exhibiting the greatest linearity was determined by graphical comparison and the color intensity of the strips observed to be inversely proportional to the concentration of As (III). Adapted field test kits were then constructed to examine water samples ranging in arsenic contamination from 0 to 50 μg L−1. A series of reactions was completed to demonstrate reproducibility and test for the accuracy of the procedure. Statistical examination of colorimetrically quantified results confirmed the hypothesis that silver nitrate can reliably and precisely expand the kit’s range of detection while maintaining its low cost, quick assessment, and uncomplicated technique. This new method, using 0.4% m/v AgNO3 as a reagent for the Gutzeit reaction, was able to distinguish between concentrations of 0, 5, 10, 15, and 50 μg L−1 at the 95% confidence level.

Undergraduate Analytical Laboratory Experiment: Determination of Arsenic in Rice with Graphite Furnace Atomic Absorption Spectroscopy and a Novel Digestion Method

Abstract: By focusing on food and a pervasive contaminant, this experiment engages student interest and effort while providing essential instruction and experience. As institutions are challenged by existing and emerging budgetary constraints, this experiment offers a determination approach employing commonly available instrumentation, the graphite furnace atomic absorption spectrometer. The module provides a broad range of experiences: it introduces the lyophilizer, offers practice in a multistep novel digestion method, presents the theoretical foundation and practical application of atomic absorption spectroscopy, and provides an opportunity to record, calculate, and report findings. Students whose math skills are in development can complete it successfully because algebraic calculations are used at each stage of the materials’ examination. Finally, when their reports align with extensive international research, the lab offers students assurance of their growing scientific competence.