A molecularly imprinted polymer with flash column chromatography for the selective and continuous extraction of diphenyl amine

Abstract

The aim of this study was to prepare MIP for the selective recognition of DPA and its combination with flash column chromatography for the continuous extraction of DPA from ammunition waste. The DPA-MIP was prepared by free radical polymerization using methacrylic acid as a complexing monomer and EGDMA as a crosslinker. Methanol and acetic acid (9:1) were used as a leaching agent for DPA. MIP showed maximum adsorption capacity at pH 4. The maximum experimental adsorption capacity obtained for MIP and NIP particles were 31 mg g -1 and 10.2 mg g -1 , respectively. Langmuir and Freundlich adsorption isotherm models were used to analyze the experimental data of DPA adsorption on MIP. Freundlich adsorption isotherm model was very well fitted with this. Pseudo first order and pseudo second order kinetic models were used to estimate corresponding rate parameters, equilibrium capacities and correlation coefficients. Selectivity coefficients of MIP for DPA in presence of NDPA, TNT and Tetryl were 23.14, 47.07 and 52.30, respectively. Continuous extraction of DPA was done with help of flash chromatography combined with MIP and showed more than 98 % recovery. MIP frequencies at 3378 cm -1 (secondary amine) and 1580 and 1486 cm -1 (aromatic -C=C-). It also shows aromatic -C-H bending frequencies at 683 cm -1 and 748 cm -1 respectively. None of these DPA peak is observed in MIP indicating complete leaching of DPA form the polymer matrix.From the FTIR studies of MIP, MIP-DPA and NIP it is shown that all shows -C=O stretching frequency at 1730 cm -1 , -C-O stretching at 1150 cm -1 indicating similarity of polymer nature ( fig. 3). In case of MIP-DPA, the peak at 1580 cm -1 is characteristic of DPA, which is absent in both MIP and NIP respectively as shown in fig. 3. Fig. 2 FTIR spectra of DPA, MAA, EGDMA and MIPwhere ‫ܭ‬ and ݊ are the Freundlich constants, which affects the adsorption capacity and the intensity of the adsorption, respectively. Freundlich isotherm parameters were estimated by plotting ‫ݍ݈݃‬ versus ‫ܥ݈݃‬ as shown in fig. 8 (b). All the estimated data obtained from Langmuir and Freundlich isotherm model is shown in table 1. As seen in fig. 8 (b), it is suggested that Fraundlich adsorption isotherm model with R 2 0.998 is very well fitted as compare to the Langmuir model for the adsorption of DPA on MIP. Thus, Freundlich isotherm model suggests multilayer chemisorption of DPA on MIP. Fig. 8 a) Langmuir and b) Freundlich adsorption isotherm plots for adsorption of DPA on the MIP and NIP particles

Chitosan-Based Lead Ion-Imprinted Interpenetrating Polymer Network by Simultaneous Polymerization for Selective Extraction of Lead(II)

“…From the FE-SEM images, a porous polymer network has been observed, as shown in Figure a. It has been observed in the literature that a MAA–EGDMA-based polymer synthesized by free-radical polymerization showed particle sizes in the range of 30–100 nm . The FE-SEM images showed particles in the range of 30–50 nm.…”

“…It has been observed in the literature that a MAA− EGDMA-based polymer synthesized by free-radical polymerization showed particle sizes in the range of 30−100 nm. 46 The FE-SEM images showed particles in the range of 30−50 nm. There is always disagreement in the literature regarding the effect of the template on the particle size of the polymer.…”

An Efficient Method for Determination of the Diphenylamine (Stabilizer) in Propellants by Molecularly Imprinted Polymer based Carbon Paste Electrochemical Sensor

“…The DPA-MIP was synthesized by radical polymerization method [14,15]. The polymer was synthesized using DPA (template), methacrylic acid (MAA) (monomer), ethylene glycol dimethacrylate (EGDMA) (crosslinker), AIBN (radical initiator), and acetonitrile.…”

Synthesis of Nickel Vanadate Anchored on Reduced Graphene Oxide for Electrochemical Determination of Antioxidant Radical Cations of Diphenylamine H•+

“…Hence, DPA fixation is of considerable importance for the accurate detection of DPA in fruit and green tea samples . Owing to the detection urgency, several analytical techniques have been developed to determine DPA, including spectrofluorometric, gas chromatography, mass spectrometry, and electrochemical methods. − Among these, electrochemical strategies are mostly preferred due to their simplicity, low price, rapid reaction, practicality, better sensitivity, and good selectivity. , …”