Molecular imprinting technology (MIT), often described as a method of making a molecular lock to match a molecular key, is a technique for the creation of molecularly imprinted polymers (MIPs) with tailor-made binding sites complementary to the template molecules in shape, size and functional groups. Owing to their unique features of structure predictability, recognition specificity and application universality, MIPs have found a wide range of applications in various fields. Herein, we propose to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs. The fundamentals of MIPs involving essential elements, preparation procedures and characterization methods are briefly outlined. Smart MIT for MIPs is especially highlighted including ingenious MIT (surface imprinting, nanoimprinting, etc.), special strategies of MIT (dummy imprinting, segment imprinting, etc.) and stimuli-responsive MIT (single/dual/multi-responsive technology). By virtue of smart MIT, new formatted MIPs gain popularity for versatile applications, including sample pretreatment/chromatographic separation (solid phase extraction, monolithic column chromatography, etc.) and chemical/biological sensing (electrochemical sensing, fluorescence sensing, etc.). Finally, we propose the remaining challenges and future perspectives to accelerate the development of MIT, and to utilize it for further developing versatile MIPs with a wide range of applications (650 references).

http://ir.yic.ac.cn/bitstream/133337/17045/1/Molecular%20imprinting%20perspectives%20and%20applications.pdf

Molecular imprinting: perspectives and applications

Aromatic amines from azo dye reduction: status review with emphasis on direct UV spectrophotometric detection in textile industry wastewaters

Advanced oxidation processes (AOPs) generating nonselective hydroxyl radicals (HO*) provide a broad-spectrum contaminant destruction option for the decontamination of waters. Halide ions are scavengers of HO* during AOP treatment, such that treatment of saline waters would be anticipated to be ineffective. However, HO* scavenging by halides converts HO* to radical reactive halogen species (RHS) that participate in contaminant destruction but react more selectively with electron-rich organic compounds. The effects of Cl-, Br-, and carbonates (H2CO3+HCO3-+CO3(2-)) on the UV/H2O2 treatment of model compounds in saline waters were evaluated. For single target organic contaminants, the impact of these constituents on contaminant destruction rate suppression at circumneutral pH followed the order Br->carbonates>Cl-. Traces of Br- in the NaCl stock had a greater effect than Cl- itself. Kinetic modeling of phenol destruction demonstrated that RHS contributed significantly to phenol destruction, mitigating the impact of HO* scavenging. The extent of treatment efficiency reduction in the presence of halides varied dramatically among different target organic compounds. Destruction of contaminants containing electron-poor reaction centers in seawater was nearly halted, while 17beta-estradiol removal declined by only 3%. Treatment of mixtures of contaminants with each other and with natural organic matter (NOM) was evaluated. Although NOM served as an oxidant scavenger, conversion of nonselective HO* to selective radicals due to the presence of anions enhanced the efficiency of electron-rich contaminant removal in saline waters by focusing the oxidizing power of the system away from the NOM toward the target contaminant. Despite the importance of contaminant oxidation by halogen radicals, the formation of halogenated byproducts was minimal.

Effect of halide ions and carbonates on organic contaminant degradation by hydroxyl radical-based advanced oxidation processes in saline waters.

Atmospheric amines - Part I. A review

The aim of this work is to present experimental results on the removal of nitrate by nitrate selective ion exchange resin, Purolite A 520E. The resin dose as the optimum condition for nitrate removal was determined. Adsorption isotherm has been modelled by Langmuir and Dubinin-Radushkevich (DR) equations. Nitrate removal by strong base anion exchange resin Purolite A 520E was also carried out with column method. The existence of chloride and sulfate ions influenced the breakthrough capacity of the resin for nitrate. Nitrate was also effectively removed from the ground water. The nitrate sorbed on Purolite A 520E was quantitatively eluted with 0.6 M NaCl.

Removal of nitrate from aqueous solution by nitrate selective ion exchange resins

Recent advances in applications of single-drop microextraction: A review

Pre-column conversion of ammonia and a number of aliphatic amines into phenylthiourea or its derivatives by reaction with phenyl isothiocyanate, followed by HPLC, has been used for their determination in environmental waters. Optimum conversion was found when the reaction was carried out in sodium hydrogencarbonate–carbonate medium at 40°C for 15 min. Well separated peaks were obtained on a C18 column with an acetonitrile–water gradient (1 ml min–1) of 30% acetonitrile for an initial 5 min which was increased linearly to 100% over 15 min and then maintained isocratic for 5 min, the acetonitrile ratio finally being returned to 30% in 5 min. The derivatized analytes were subjected to off-line solid phase extraction on C18 sorbent. A linear calibration graph was obtained for 0.01–10 mg l–1 analytes with a correlation coefficient of 0.9954 for ammonia and in the range 0.9982–0.9996 for amines. The limit of detection for ammonia was 0.2 µg l–1 and for amines in the range 0.3–0.6 µg l–1. The method was applied to tap, underground, river and aquarium waters, the recovery being in the range 97–106% (RSD 1.8–4.5%). Many of the samples were found to contain more than the permissible limit of ammonia. Phenyl isothiocyanate is stable for long periods in aqueous medium over wide ranges of pH and temperature, and the resulting phenylthioureas have adequate retention on C18 sorbent and strong UV absorption, making this reagent suitable for the determination of amines in water.

/pdf/determination-of-ammonia-and-aliphatic-amines-in-jruptp4vck.pdf

Determination of ammonia and aliphatic amines in environmental aqueous samples utilizing pre-column derivatization to their phenylthioureas and high performance liquid chromatography

Single drop microextraction or solid phase microextraction-gas chromatography-mass spectrometry for the determination of iodine in pharmaceuticals, iodized salt, milk powder and vegetables involving conversion into 4-iodo-N,N-dimethylaniline.

Liquid-phase microextraction-gas chromatography-mass spectrometry for the determination of bromate, iodate, bromide and iodide in high-chloride matrix

Low concentrations of phenols and amines in environmental 
waters and their low breakthrough volume during solid-phase extraction 
(SPE) hinder the detection of phenols and aromatic amines, whereas ammonia 
and aliphatic amines are not suitable for SPE. Pre-column derivatization to 
arylbenzoates and N-alkyl- or N-arylbenzamides and their 
GC-MS is proposed to separate and determine phenols and amines in aqueous 
samples in the range 0.1–100 μg l−1 with 
correlation coefficients in the range 0.9910–0.9992. The limit of 
detection ranged from 7 to 39 ng l−1 for most analytes (90 
ng l−1 for 2,3,6-trichlorophenol and 20 μg 
l−1 for ammonia) when 80 ml of sample were 
preconcentrated, after derivatization, on a styrene–divinylbenzene 
copolymer sorbent. The developed method was applied to spiked drinking 
water, groundwater and river water samples, and was used to detect 
halo-phenols in paper mill effluents. The average recovery ranged from 96 
to 110% with RSD of 4–12%. The described method is rapid and can be 
applied to control the water quality of environmental waters with respect 
to three important classes of organic pollutants and ammonia.

Simultaneous determination of ammonia, aliphatic amines, aromatic amines and phenols at μg l−1 levels in environmental waters by solid-phase extraction of their benzoyl derivatives and gas chromatography-mass spectrometry

Archana Jain

Papers

Recent advances in applications of single-drop microextraction: A review

Determination of ammonia and aliphatic amines in environmental aqueous samples utilizing pre-column derivatization to their phenylthioureas and high performance liquid chromatography

Single drop microextraction or solid phase microextraction-gas chromatography-mass spectrometry for the determination of iodine in pharmaceuticals, iodized salt, milk powder and vegetables involving conversion into 4-iodo-N,N-dimethylaniline.

Liquid-phase microextraction-gas chromatography-mass spectrometry for the determination of bromate, iodate, bromide and iodide in high-chloride matrix

Simultaneous determination of ammonia, aliphatic amines, aromatic amines and phenols at μg l−1 levels in environmental waters by solid-phase extraction of their benzoyl derivatives and gas chromatography-mass spectrometry