Cloud point extraction of vanadium in parenteral solutions using a nonionic surfactant (PONPE 5.0) and determination by flow injection-inductively coupled plasma optical emission spectrometry.

A preconcentration and determination methodology for vanadium at trace levels in parenteral solutions was developed. Cloud point extraction was successfully employed for the preconcentration of vanadium prior to inductively coupled plasma atomic optical emission spectrometry (ICP-OES) coupled to a flow injection (FI) system. The vanadium was extracted as vanadium-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol [V-(5-Br-PADAP)] complex, at pH 3.

Trace humic and fulvic acid determination in natural water by cloud point extraction/preconcentration using non-ionic and cationic surfactants with FI-UV detection.

A preconcentration and determination method for humic and fulvic acids at trace levels in natural water samples was developed. Cloud point extraction was successfully employed for the preconcentration of humic acid (HA) and fulvic acid (FA) prior to the determination by using a flow injection (FI) system coupled to a spectrophotometric UV-Vis detector. The quantitative extraction of HA and FA within the pH range 1-12 was obtained by neutralization of the anionic charge on the humic substances with a cationic surfactant, hexadecyltrimethylammonium bromide (CTAB).

On-line preconcentration and determination of chromium in parenteral solutions by flow injection-flame atomic absorption spectrometry.

An on-line chromium preconcentration and determination system implemented with flame atomic absorption spectrometry (FAAS) associated to flow injection (FI) was studied. For the retention of chromium, 4-(2-Thiazolylazo)-resorcinol (TAR) and Amberlite XAD-16 were used, at pH 5.0.

On-line preconcentration and determination of cadmium in honey using knotted reactor coupled to flow injection-flame atomic absorption spectrometry.

An on-line cadmium preconcentration and determination system implemented with flame atomic absorption spectrometry (FAAS) associated with flow injection was studied. Cadmium was retained as Cd-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol Cd-(5-Br-PADAP) complex, pH 9.3.