Spectrophotometric Determination of Cadmium Using Thiazolylazo Chromogenic Reagents in the Presence of Triton X-100: Application in Environmental Samples

Abstract

A highly sensitive, selective, and accurate spectrophotometric method for the determination of cadmium using some thiazolylazo (I-V) chromogenic reagents has been developed. In the presence of Triton X-100 and NH 3 /NH 4 Cl buffer solutions, the optimum conditions for complexation, stoichiometric ratio, and stability constants are studied. Beer's law is obeyed up to at least 4.4 µg/10 ml of cadmium. A limit of detection and quantifications of 0.96 and 3.3 ng ml −1 have been estimated and a coefficient of variation of 1.9% at the 3.0 µg level was found. The molar absorptivity and Sandell sensitivity for each reagent are calculated. The only species that interfere seriously are Hg 2+ and Ni 2+ . The method has been applied to determine cadmium in water samples, and plant materials, and compared statistically with the AAS method. Interferences were overcome by using mixed 163 ORDER REPRINTS AMINmasking agents and preliminary extraction into Aliquat 366/ carbon tetrachloride.

Microdetermination of Zinc(ii) in Alloys and Ores by Visible Spectrophotometric Technique Using 2,3-Dichloro-6- (2-Hydroxynaphthylazo)- Quinoxaline in Presence of Mixed Surfactants

“…(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) The enhancement of the colour reactions of metal ions with chelating dyes by the presence of surfactants provides an inexpensive alternative to atomic spectroscopy methods, for meeting the present demands for determination of ever lower concentrations of elements. The coloured complexes formed in micellar media are characterized 586 AMIN ORDER REPRINTS by high molar absorptivity (often <10 5 l mol À1 cm À1 ) and high stability over a wide pH range, and usually by a large bathochromic shift caused by addition of surfactants to the binary complex formed.…”

Ultra-sensitive spectrophotometric determination of nickel after complexation and membrane filtration

“…Spectrophotometry is the most common technique used for metal determination using various chromogenic reagents [1][2][3][4][5][6][7][8], owing to its simplicity and low cost. However, the spectrophotometric determination of metals at trace level in solution is difficult due to various factors, particularly their low concentrations and matrix effects.…”

An ionic liquid-based microextraction method for highly selective and sensitive trace determination of nickel in environmental and biological samples

“…Thus, extraction procedures based on these reagents could be prone to suffer from matrix interferents occurring in real complex samples. On the other hand, BTAHQ forms stable complexes with numerous metal ions [28][29][30][31][32][33] and it can selectively react with nickel under specic conditions. Moreover, BTAHQ has been employed for the spectrophotometric determination of nickel in the past, 28 but no report has been so far published regarding its use and combination with RTILs, for development of LLME procedures.…”