Low waste generation represents a comprehensive orientation in analytical chemistry. It also forms a goal of flow injection analysis (FIA). The current research aims at modifying the injection part of the lucigenin-H2O2-OH- Pb(II) chemiluminescence detection system with flow injection analysis (FIA-CL) for an online Pb(II) analysis. The modified system was employed to determine the Pb(II)concentration. This was followed by treatment with crude tomato peels as an absorbent as tomato peels were treated with NaOH, carbonized tomato peels with HCl, and carbonized tomato peels with H2SO4. Under optimum experimental conditions, a calibration graph, represented by peak height (mV), was constructed based on plotting the chemiluminescence (CL) intensity, against (μg.ml−1) Pb(II) concentration, 10–90 μg.ml−1 range, 0.9913 correlation coefficient. Langmuir and Freundlich, used as isotherm models to verify the equilibrium results. The adsorption of Pb(II) on crude tomato peels and treated tomato peel was followed by the Langmuir model due to the high correlation coefficient (R2).

In this study, dibenzo crown ether (DB18C6) is used to chemically modify the Electrospun Polyethylene Terephthalate (PET) nanofibers. The main parameters influence on the PET nanofiber’s surface modification with crown ether concentration and other solvents has been tested. The PET nanofibers with and without (DB18C6) are put into comparison by scrutinizing FTIR, TGA, SEM, and EDX results. It is to be mentioned that the modification of the PET nanofibers with crown ether is utilized for the extraction of methylene blue (MB) from aqueous solutions. For the purpose of evaluating the potential of the chemically modified PET nanofibers as adsorbents to remove MB from aqueous solutions, experiments of batch adsorption are carried out. The effect of MB concentration, solution pH, and shaking time are optimized. Several isotherm models such as Langmuir, Freundlich, Tempkin, and Dubinin - Radushkevich (D-R) equations are utilized to test the equilibrium results. Owing to the high correlation coefficient (R2), the adsorption of MB into the modified PET is detected through Langmuir model. ΔGo, ΔHo, and ΔSo quantities are estimated. The negative ΔG° values, the positive ΔHo, and ΔSo values indicate that the adsorption process is spontaneous and endothermic.

The present research study investigates the potential use of the novel polyethylene terephthalate (PET) nanofibers extracted from waste bottles. The electrospinning process creates nanofibers which are then impregnated with dibenzo-18-crown-6 (DB18C6) (crown ether) to obtain a modified PET nanofiber. The use of modified PET nanofibers to remove methylene blue (MB) from aqueous solutions at different contact times, temperatures and initial dye concentrations is the prime concern of the present study. The amount of MB adsorbed at equilibrium (qe) is calculated at different temperatures (303, 313, and 323 K) and different concentrations (5, 10, 15 mg/g). The Kinetic and equilibrium studies of MB removal are carried out. The results indicate that the adsorption kinetics of MB can be described by the pseudo-second-order model. The activation energy value is below 40 kJ/mol and this gives an idea about the physisorption process.

This study reports a new, rapid and sensitive flow injection analysis (FIA) with peroxyoxalate chemiluminescence detection (PO-CL) for determination of hydrogen peroxide through merging zone principle. Di (N-Succinimidyl) oxalate was applied for the first time as peroxyoxalate chemiluminescence reagent. The CL was produced by the oxidation of Di (N-Succinimidyl) oxalate by hydrogen peroxide in the presence of a fluorescent compound, (9, 10 Bis phenyl ethynyl anthracene) and imidazole as a catalyst. Various parameters associated with this flow system were studied and essential optimizations were carried out. Calibration graph was constructed for determination of hydrogen peroxide in the range (0.02-0.34 mol.L–1) with correlation coefficient (R2) (0.982).The method was applied successfully for the determination of hydrogen peroxide in commercial pharmaceutical products and in tap water.