Determination of subnanomolar concentrations of vanadium in environmental water samples using flow injection with luminol chemiluminescence detection

Abstract

A flow injection chemiluminescence method is described for the determination of subnanomolar concentrations of vanadium in environmental water samples. The procedure is based on the oxidation of luminol in the presence of dissolved oxygen catalyzed by vanadium(IV). Vanadium(V) reduction and preconcentration of vanadium(IV) was carried out using in-line silver reductor and 8-hydroxyquinoline chelating columns at pH 3.15, respectively. The calibration graph for vanadium(IV) was linear in the concentration range of 0.025-10 µg/L with relative standard deviation in the range of 0.4-5.58%. The detection limit (3s blank) was 3.8 × 10(-3) µg/L without preconcentration; when the vanadium(IV) was preconcentrated with an 8-HQ column for 1 min (2.0 mL of sample loaded), the detection limit of 5.1 × 10(-4) µg/L was achieved. One analytical cycle can be completed in 2.0 min. The analysis of certified reference materials (CASS-4, NASS-5 and SLRS-4) by the proposed method showed good agreement with the certified values. The method was successfully applied to the determination of total dissolved vanadium in environmental water samples.

Determination of Arsenic by ICP‐OES after Cloud Point Extraction with Salt Induced Phase Separation: Application to Gadolinium Based MRI Contrast Agent**

“…This reaction gave rise to classical gravimetric or colorimetric methods and has long been used in a variety of analytical procedures for arsenic determination where derivatization step is required. [24,25] It has to be noted, that such reaction is applicable only for arsenic in oxidation state + 5 extraction, which allows using it for As(V) speciation. [3]…”

“…This reaction gave rise to classical gravimetric or colorimetric methods and has long been used in a variety of analytical procedures for arsenic determination where derivatization step is required [24,25] …”

Development of a chemiluminescent enzyme immunoassay for the determination of dexamethasone in milk

“…High sensitivity of luminol oxidation to the addition of different compounds is a well known fact. [41][42][43] Contrary to Carrez solution and trichloroacetic acid, while using methanol (25% v/v) to precipitate milk proteins, the precision of the DEX concentrations values measured by CL-ELISA was good (CVs were less than 14%). Moreover, as seen in Fig.…”

A Novel Chemiluminescence Assay of Ethylene Glycol in Antifreeze Samples using FIA with Merging Zone Principle

“…Luminol (5-Amino-2,3-dihydro-1,4-phthalazinedione)is the most widely used CL reagent. The CL emission of luminol is based on its oxidation by various oxidizing agents in the alkaline medium [20][21][22].…”