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In present study, the molecular imprinting polymer (MIP) of p-coumaric acid was synthesized by using p-coumaric acid as a template, acetonitrile as solvent, 1,4-butanediol dimethacrylate as cross-linker, acrylic acid as monomer and 2,2-azobisisobutironitrile (AIBN) as the initiator. The synthesized polymers were characterized by FTIR and SEM. The results from SEM revealed that the polymer was in spherical shape with size in micro-range. The binding efficiency of polymers was analyzed by adsorption study. The highest rebinding efficiency for MIP was ~ 80% while for non-imprinted polymer (NIP) it was only 24%.

Molecularly imprinted polymers (MIPs) of melamine (MEL) were synthesized by non-covalent approach with precipitation polymerization. In this research, MEL was used as the template molecule,...

Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using thymol as a template molecule, acrylamide as a functional monomer and N,N-methylbisacrylamide as the crosslinker with a non-covalent approach. The polymers were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), fourier-transform infra red spectroscopy(FT-IR) and Brunauer-Emmett-Teller (BET). The SEM results depicted that the shape of polymer particles is spherical with uniform size (micro-meters). The BET results also showed better surface area, pore size and pore volume of MIP as compared to non-imprinted polymer (NIP). A series of parameters such as initial concentration, polymer dosage, effect of pH and slectivity with structural analogue were conducted. The selectivity of MIP towards thymol was appreciable as compared to its structural analogue gallic acid with a relative selectivity coefficient of 3.59. Finally, MIP has been successfully used for extraction of thymol from the spiked blood serum (84 %) and river water sample (98 %).

The molecular imprinting technique is used to create the molecularly imprinted polymers (MIPs) with higher binding capacity towards the template. In this research precipitation polymerization method with noncovalent approach was used to synthesize imprinted polymer microspheres. The polymerization reaction was conducted in a flask containing acetonitrile as a porogen, cinnamic acid as a template (T), acrylic acid (AA) as a monomer, divinylbenzene (DVB) as a cross-linker, and azobisisobutyronitrile as an initiator. The polymer particles were characterized by using SEM and FTIR. The rebinding efficiency was conducted by batch binding assay and the results were monitored by using HPLC. The batch binding results suggested MIP1 (T : AA : DVB, 1 : 6 : 20 molar ratio) is most suitable composition for the rebinding of cinnamic acid. The highly selective polymer (MIP1) was used for the extraction of cinnamic acid from human plasma. The extraction efficiency of imprinted polymer of cinnamic acid from spiked plasma was above 75%.

The nature of caffeine reveals that it is a bitter white crystalline alkaloid. It is a common ingredient in a variety of drinks (soft and energy drinks) and is also used in combination with various medicines. In order to maintain the optimum level of caffeine, various spectrophotometric methods have been developed. The monitoring of caffeine is very important aspect because of its consumption in higher doses that can lead to various physiological disorders. This paper incorporates various spectrophotometric methods used in the analysis of caffeine in various environmental samples such as pharmaceuticals, soft and energy drinks, tea, and coffee. A range of spectrophotometric methodologies including chemometric techniques and derivatization of spectra have been used to analyse the caffeine.

The chromatography of four cationic surfactants was performed on silica high performance thin-layer plates with mixed solvent system of methanol and ethylenediaminetetraacetic acid (EDTA). The resolution of a mixture of Benzyltrimethylammonium chloride (BTAC), Dodecyltrimethylammonium chloride (DTAC), Tetrabutylammonium bromide (TBAB), and Methyltrioctylammonium bromide (MTOB) was achieved by using methanol:5% aqueous EDTA (7:3,v/v) as a solvent system. The effect of concentration of EDTA on the mobility of all the four cationic surfactants was examined. The limit of detection of BTAC, DTAC, TBAB, and MTOB estimated was 0.65, 0.15, 0.15, and 0.31 µg/zone, respectively. The developed method was utilized to identify these surfactants in different spiked water samples after their preliminary separation.

The activated carbon (AC), prepared at different burn-off rates, showed a high uptake of methylene blue. At 93% burn-off, methylene blue uptake was 620 mg/g. Adsorption capacity of microcystin-LR onto rubber wood AC was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and temperature. Microcystin-LR removal is pH dependent and found to be highest at pH 2.5. Increases in adsorption capacity with increase in temperature indicate that the adsorption reaction is endothermic. Based on this study, the thermodynamic parameters like standard Gibb9s free energy (Δ G °), standard enthalpy (Δ H °) and standard entropy (Δ S °) were evaluated. A pseudo second order model was found to explain the kinetics of microcystin-LR adsorption most effectively. The rate of intraparticle diffusion was also evaluated. The Langmuir and Freundlich isotherms were used to describe the adsorption equilibrium studies of rubber wood AC at different temperatures. The Langmuir isotherm shows better fit than Freundlich isotherms in the temperature range studied. The results show that the rubber wood AC can be efficiently used for the removal of microcystin-LR from water. In order to investigate the possibility of regeneration and reuse of exhausted adsorbent, desorption studies were also performed.

This review incorporates a large number of chromatographic systems modified by the surfactants. A large number of solvent systems and stationary phases are summarized in this paper. Three different kinds of surfactants (anionic, cationic, and nonionic) are used as modifiers for stationary phases as well as solvent systems. Surfactants are used at all the three different concentration levels (below, above, and at critical micelle concentration) where surfactants behave differently. Modifications of both stationary phases and solvent systems by surfactants produced a new generation of chromatographic systems. Microemulsion solvent systems are also incorporated in this paper. Microemulsion thin-layer chromatography is a new approach in the field of chromatography.

Thin-layer chromatography is a versatile separation technique and is compatible to almost all types of compounds available in nature. This review presents numerous chromatographic systems developed for the analysis of amino acids. The stationary phases, solvent systems, and detection reagents used by the various chromatographers are incorporated in this review. From the available literature, it is obvious that amino acids have been greatly analyzed by thin-layer chromatography.

Thin-layer chromatographic analysis of surfactants is presented in this review. Various chromatographic systems useful for the identification, separation and quantification of surfactants are reported. New approaches in thin-layer chromatography enable analysts to separate and determine surfactants in complex mixtures (in various environmental samples). Thin-layer chromatographic methods are mainly used for the separation of surfactants either in the separation of different classes or separation of different groups within the same class.

Cannabis sativa, Myristica fragrans, Piper longum and Embleia ribes are the active pharma ingredients of an ayurvedic herbal formulation Jatiphaldya, which is beneficial in many typical stomach related disorders. The present study is aimed to develop a simple and reliable thin layer chromatographic (TLC) method using micellar solution of sodium dodecyl sulfate (SDS) as mobile phase for the identification of all the four herbal drugs with preliminary separation on silica gel 'G' TLC plate. The active components of drug were extracted in a mixture of ethanol and water (4:1), chromatographed on silica gel TLC plate using aqueous SDS (5%) as mobile phase and the resolved spots for Cannabis sativa (RF-0.95), Myristica fragrans (RF-0.64), Piper longum (RF-0.41) and Embleia ribes (RF-0.26) were identified using vanillin-sulfuric acid (2% solution of vanillin in 5% methanolic sulfuric acid). In order to realize most favorable mobile phase system in combination with silica gel 'G' as stationary phase, the effect of nature of surfactants (anionic, cationic or nonionic) and the level of concentration of each surfactant (sodium dodecyl sulfate (SDS), N-cetyl-N, N, N-trimethylammonium bromide (CTAB) or t- octyl phenoxydacaethoxy ethanol (TX-100)) on the mobility of all four active components was examined. In addition, the effect of organic (urea and alkanols) and inorganic (NaCl) additives in 5% aqueous SDS solution on mobility pattern of active herbal pharma ingredients was examined. The presence of ammonia and nitrate in the drug sample was found to hamper the resolution and identification of all active components. However, NaCl, KCl and glucose do not offer serious interference.

Separation studies of four surfactants (nonionic and cationic) were performed on silica high-performance thin-layer chromatographic plates with various solvent systems. The most useful chromatographic system for the mutual separation of coexisting polyoxyethylene (20) stearyl ether (C18EO20), cetylpyridinium chloride (CPC), tetradecyl trimethyl ammonium bromide (TTAB) and polyoxyethylene (9.5), octyl phenyl ether (OPEO9.5) was formamide + 1 M formic acid (50:50 v/v). The nature of ‘H’ and ‘H+’ of formic acid (H–COO−H+) on the mobility of these surfactants was studied. The interference due to the presence of metal cations as impurities on the resolution of mixture of C18EO20, CPC, TTAB and OPEO9.5 was also examined. The limits of detection of C18EO20, CPC, TTAB and OPEO9.5 estimated were 0.0620, 0.0310, 0.0625 and 0.0312 μg/zone, respectively. The practical applicability of the proposed method was tested for the identification of four coexisting surfactants after their separation from the spiked aqueous systems.

The separation efficiency of micellar solutions in thin layer chromatography of hydrophilic vitamins (B1, B9, B12 and C) has been examined using silica gel as stationary phase. The best results were obtained with mixed micelles (aqueous solution of anionic SDS (0.5%) plus non-ionic Triton X-100 (0.5%) surfactants) and butanol (9:1 v/v) as mobile phase. The proposed method is applicable to the identification and separation of vitamins (B1, B9 and C) present in drug samples (Becosule and Celin). The separation 1 μg of vitamin C from milligram quantities (up to 0.50 mg) of vitamin B1 has been successfully realized. Effect of metal ions as impurities on the separation of B1, B9 and vitamin C and limit of detection of these vitamins have been examined.

Thin-layer chromatography (TLC) of three cationic surfactants was performed on silica TLC plates with various solvent systems. The mutual separation of cetylpyridinium chloride (CPC), tetradecyltrimethylammonium bromide (TTAB) and dodecyltrimethylammonium bromide (DTAB) was achieved on silica TLC plates with ethanol: 1% aqueous ammonium chloride (4:6, v/v) as an eluent. Effects of cations and anions in the mobile phase on mobility and separation of CPC, TTAB and DTAB were examined. The interference due to the presence of metal cations as impurities on the resolution in the mixture of CPC, TTAB and DTAB was also examined. The limits of detection of CPC, TTAB and DTAB estimated were 0.015, 0.031 and 0.062 μg zone−1, respectively. The developed method was utilized to identify these surfactants in different spiked water samples after their preliminary separation.

Molecularly imprinted polymer (MIP) microspheres for Piperine were synthesized by precipitation polymerization with a noncovalent approach. In this research Piperine was used as a template, acrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and 2,2′-azobisisobutyronitrile (AIBN) as an initiator and acetonitrile as a solvent. The imprinted and nonimprinted polymer particles were characterized by using Fourier transform infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). The synthesized polymer particles were further evaluated for their rebinding efficiency by batch binding assay. The highly selected imprinted polymer for Piperine was MIP 3 with a composition (molar ratio) of 0.5 : 3 : 8, template : monomer : cross-linker, respectively. The MIP 3 exhibits highest binding capacity (84.94%) as compared to other imprinted and nonimprinted polymers. The extraction efficiency of highly selected imprinted polymer of Piperine from spiked urine was above 80%.

The chromatographic separation of three metal cations was performed on high-performance thin-layer plates (silica gel 60F254) with mixed sodium dodecyl sulphate (SDS) and oxalic acid. The effect of concentration of surfactant and additive effect of different carboxylic acids on the mobility of metal ions were investigated. The resolution of a mixture of Pb2+, Ni2+, and Co2+ was achieved by using 0.2 M SDS plus 0.08 M oxalic acid, 1:9, v/v as a solvent system. The developed method was utilized to identify these metal ions in different spiked water samples after their preliminary separation.

Thin layer chromatography has been used for the analysis of natural and synthetic steroids in various environmental materials. This review focuses mainly on steroid analysis in environmental materials such as pharmaceuticals, plant products and other biological specimens. The most widely investigated biological specimens are urine and blood plasma or serum. Various chromatographic systems useful for the identification; separation and quantification of surfactants are also reported in this review. Keywords: Steroids; Thin layer chromatography; Environmental materials; Biological specimens