Search

The high toxicity of the cyanide ion at low concentration necessitates its analysis in a variety of environmental samples with a very low cyanide content. A new sensitive spectrophotometric method has been developed for the trace determination of cyanide with ninhydrin (NH) in an alkaline medium. Beer’s law is obeyed in the range of cyanide concentration 0.04 - 0.24 µg cm-3, and the molar absorptivity at 590 nm is 2.20 × 105dm3mol-1cm-1. The Sandell’s sensitivity of the product is 0.000118 µg cm-2. The optimum reaction conditions and other important analytical parameters have been investigated. The results obtained by using the proposed method for environmental samples agree well with those obtained by the Aldridge standard method.

A sensitive spectrophotometric method for the determination of silver is described. The reaction involves a silver-enhanced reduction of 2,3,5-triphenyl-2.ff-tetrazolium chloride by semicarbazide hydrochloride to yield a pink-colored product with maximum absorption at 510 nm. Beer’s law is obeyed in the concentration range of 0.02 - 0.34 μg cm4of silver, and the molar absorptivity is 4.51 × 1051 moH cm-1. The optical parameters, optimum reaction conditions and interference studies have been described. The method has been applied to the determination of silver in photographic film waste water and in synthetic samples.

2-Chloro-3-(β-nitrovinyl)quinoline (CNQ) was crystallographically studied owing to its medicinal properties and its occurrance in numerous commercial products, including pharmaceuticals, fragrances and dyes. The vinyl group is planar, and takes up an extended conformation. An hydrogen bonding of C-H···N type helps to stabilize the molecules in the unit cell.