Micell-mediated extraction for the spectrophotometric determination of nitrite in water and biological samples based on its reaction with p-nitroaniline in the presence of diphenylamine

Flame atomic absorption spectrometric determination of trace quantities of cadmium in water samples after cloud point extraction in Triton X-114 without added chelating agents

“…Compared with conventional solvent extraction, CPE uses water and avoids the use of large amounts of expensive, toxic and flammable organic solvents. In addition, CPE can lead to higher recovery efficiency and a large preconcentration factor because the presence of surfactant can minimize losses of analytes due to their adsorption onto the container [6]. The CPE method has been used for the preconcentration of metal ions, after the formation of sparingly water-soluble complexes, as a prior step to their determination by FAAS [7][8][9][10][11][12][13][14][15].…”

Partition/Ion-Exclusion Chromatographic Ion Stacking for the Analysis of Trace Anions in Water and Salt Samples by Ion Chromatography

“…Although a lot of spectrophotometric [1][2][3][4][5][6][7][8][9] and electrochemical [10][11][12] methods have been reported for the measurement of some inorganic anions, ion chromatography is perhaps the most accepted technique for monitoring inorganic anions in water samples. [13][14][15][16][17] Nevertheless, there is a need to find effective and fast preconcentration techniques for increasing the sensitivity of detection because it is often difficult to detect low level inorganic anions in the presence of a large excess of foreign ions directly by spectrophotometric and conductivity measurements.…”

Griess micro-assay for the determination of nitrite by combining fibre optics-based cuvetteless UV–Vis micro-spectrophotometry with liquid-phase microextraction

“…Nevertheless, the colorimetric standard Griess assay for nitrite determination [19] is not sensitive enough to be directly applied to water samples. Therefore, in order to circumvent the low sensitivity of spectrophotometric methods, several sample preparation techniques such as solid-phase extraction (SPE) [20][21][22][23] or cloud point extraction (CPE) [24,25] have been developed for separation and preconcentration of nitrite in aqueous matrices prior to its spectrophotometric detection. Usually, flow injection (FIA) [22] and sequential injection systems (SIA) [21,23] have been employed to improve the sample throughput.…”