On-line column preconcentration for the determination of cobalt in sea water by flow-injection chemiluminescence detection

Abstract

A flow-injection method for the determination of dissolved cobalt(II) in sea water has been studied based on a combination of column preconcentration using 8-quinolinol immobilized on silica gel, fluoride containing metal alkoxide glass (8HQ-MAF) and chemiluminescence detection with a gallic acidhydrogen peroxide system. Co(II) is selectively recovered from an acidified sample with 8-quinolinol immobilized on silica gel. After elution with dilute hydrochloric acid the resultant eluent is mixed with the reagent solutions, heated to 60°C and then introduced into the CL cell. The analysis time including the 2-min sample load was 8 min per sea water sample with a corresponding detection limit of 0.62 ng l\ (3 ). The average standard deviation calculated for 10 replicate measurements of artificial sea water samples with a concentration of 10 ng l\ cobalt was $2.1%. The method has been tested with the standard reference sea waters NASS and CASS.

Quinoline-8-ol and Its Derivatives as Preconcentration Agents in Flow Injection Analysis Coupled to Atomic and Molecular Spectrometric Techniques

“…63 The analysis time, including a 2-min sample loading-time, was 8-min per sample with a detection limit and RSD of 0.62 ng/l and 2.1%, respectively. The method was tested with standard reference seawater samples (NASS and CASS).…”

Determination of Cobalt in Seawater Using Neutron Activation Analysis after Preconcentration by Adsorption ontoγ-MnO2Nanomaterial

“…Therefore, the separation of cobalt from the sample matrices as well as the preconcentration of cobalt is crucial for the accurate and efficient determinations of cobalt at the ultratrace levels in seawater. Various methods in addition to the modern instrumental methods have been used to enrich the level of cobalt in seawater, such as the coprecipitation [2], liquidliquid phase extraction [5], and solid phase extraction [6,7].…”

Chemiluminescence of cobalt(II)‐catalysed auto‐oxidation of sulphite and its application to cobalt analysis

“…Most of the CL methods are based on the catalysis of the reaction involving CL reagents such as luminol (1-4), lucigenin and gallic acid (5). Among them, the luminolhydrogen peroxide system is the most sensitive and a sub-fmol/L level (0.13 fmol/L) detection of Co(II) was reported (1).…”

“…In this mechanism, the trivalent metal ion initiates the chain reaction by reacting with sulphite, generating SO 3 − · . In subsequent steps, the transition metal ion is reoxidized by SO 4 − · , SO 5 − · and SO 5 2− generated in the chain reaction, and sulphate is formed as the final product (10,11,17,18). This mechanism is generally accepted and can be applicable to all catalytically active metal ions.…”