Improvement of the diphenylamine-based spectrophotometric method for nitrate determination

Abstract

The previously published diphenylamine (DPA)-based method (DPAM) for nitrate determination was investigated for its applicability using model solutions. First, the response surface methodology (RSM) was applied to elucidate whether the independent variables i.e. pH (x 1 ) and initial nitrate content (NC) (x 2 ) of samples influence the relative error (RE ¼ dependent variable) of the method or not. The model found (in coded variables) is of the type: RE ¼ 11.12 + 0.46x 1 À 15.61x 2 À 1.20x 1 x 2 + 7.44x 1 2 + 7.69x 2 2 .So, based on the response surface and iso-response curves related to model solutions, it becomes possible to minimize the RE value (<20%) by adjusting the sample pH to about 4. Based on these first results, some improvements were attempted which allowed us to reach recovery rates of (83.9 AE 9.0)% and (87.3 AE 8.9)% in the case of spiked spinach stalk and dam drinking water, respectively.

Cardioprotective molecule and bioactive compounds of some selected vegetables available in Bangladesh

“…) content: Nitrate (NO 3 -) content from fresh vegetables was measured by "Improved Diphenylamine-based Spectrophotometric Method" (Omar et al, 2013). Nitrate calibration curve (Fig.…”

Modeling of nitrate leaching kinetics during Spinach Leaf Midribs blanching

“…Determination of nitrate was performed using the spectrophotometric procedure described by Golubev [34] and improved by Aoun et al [35].…”

Zirconium(IV) Metallocavitands As Blue-Emitting Materials

“…In order to further expand the properties of zirconium metallocavitands as possible hosts for sensing applications, we investigated the synthesis of zirconium analogues containing extended cavities with nitrogen-containing carboxylate ligands. It was our interest to determine if the presence of functional groups on the organic moieties would impede the formation of the expected metallocavitands, since all half-sandwich metallocavitands reported to date only have aryl groups containing strong C–X bonds. − Also, several nitrogen-containing aromatic molecules, notably containing the carbazole and the diphenylamine moieties, exhibit interesting photoluminescence properties that could serve as spectroscopic probes for the characterization of host–guest interactions . We herein report the synthesis and characterization of four new half-sandwich metallocavitands having amino, diphenylamino, carbazolyl, and pyridyl moieties.…”