Spectrophotometric monitoring of nitrite in seawater after liquid microextraction of its derivative with 2,3-diaminonaphthalene

Abstract

A simple dispersive liquid–liquid microextraction based on solidification of floating organic droplets coupled with spectrophotometric detection was developed for the determination of nitrite in Chabahar Bay seawater. In the preparation procedure, 2,3-diaminonaphthalene as derivatization reagent reacts with nitrite in acidic medium to form a photometric center of 1-[H]-naphthotriazole (NAT). Product material (NAT) was extracted by dispersive liquid–liquid microextraction with 1-dodecanol as extraction solvent and after centrifugation, the floated droplet was solidified in an ice bath and was easily removed for analysis at λmax = 358 nm. Several important factors affecting the microextraction efficiency were optimized in artificial seawater as a best simulation media. Under the optimum conditions, the absorbance of NAT was linear with nitrite concentrations ranging from 0.1 to 11 μg/mL in seawater. Figures of merit of method such as enrichment factor (52), limit of detection (0.094 μg/mL), and repeatability (N = 6, %RSD = % 5) were evaluated as appropriate. Determination of nitrite in Chabahar coastal zone showed that nitrite concentration varied in the range of 0.77–1.76 μg/mL with an increase of concentration from South to the North of Bay.

A Facile Hydrothermal Synthesis and Electrochemical Properties of Manganese dioxide@graphitic Carbon Nitride Nanocomposite toward Highly Sensitive Detection of Nitrite

“…Thus, several analytical methods were used so far for determination and quantification of nitrite including spectrophotometry, Griess method, gas chromatography-mass spectrometry, ion chromatography, Chemiluminescence, high performance liquid chromatography (HPLC) and UV/Vis detector but each of them possess its own disadvantages such as expensive, long time process and large quantity required. [19][20][21][22][23][24] On the other hand, electrochemical method offers low cost, short response time, easy preparation and fabrication, high sensitivity and selectivity.…”