Recent Developments of Liquid Chromatography Stationary Phases for Compound Separation: From Proteins to Small Organic Compounds.

Compound separation plays a key role in producing and analyzing chemical compounds. Various methods are offered to obtain high-quality separation results. Liquid chromatography is one of the most common tools used in compound separation across length scales, from larger biomacromolecules to smaller organic compounds. Liquid chromatography also allows ease of modification, the ability to combine compatible mobile and stationary phases, the ability to conduct qualitative and quantitative analyses, and the ability to concentrate samples. Notably, the main feature of a liquid chromatography setup is the stationary phase. The stationary phase directly interacts with the samples via various basic mode of interactions based on affinity, size, and electrostatic interactions. Different interactions between compounds and the stationary phase will eventually result in compound separation. Recent years have witnessed the development of stationary phases to increase binding selectivity, tunability, and reusability. To demonstrate the use of liquid chromatography across length scales of target molecules, this review discusses the recent development of stationary phases for separating macromolecule proteins and small organic compounds, such as small chiral molecules and polycyclic aromatic hydrocarbons (PAHs).

Bentonite-based functional material as preconcentration system for determination of chromium species in water by flow injection analysis technique.

Chromium species have different level of toxicities. For example, Cr(VI) is 100 times more toxic than Cr(III). This characteristic makes speciation analysis of chromium become important. This research will discuss about a development of a Flow Injection Analysis-Atomic Absorption Spectrometry (FIA-AAS) technique that utilizes bentonite based functional material as a retention column. The separation, preconcentration and trace analysis of the Cr species in the water has been successfully performed using a Bt-MCCs mini-column in the FIA-AAS system. Analytical performance of the developed method is described as repeatability, linearity, and detection limit. Analytical performance for Cr(III) are 1.78 %, correlation coefficient 0.9975 for the concentration range of 50-600 µg.L-1, and 2.76 µg.L-1, respectively. Whereas, analytical performance for Cr(VI) are 0.60 %, correlation coefficient 0.9926 for concentration range of 50-600 µg.L-1, and 2.42 µg.L-1, respectively. This limit detection is better than the other selective method that has been reported using AAS as detector and the concentration range can be widened with this limit detection. Evaluation of FIA performance for both of Cr(III) and Cr(VI)is that it has an enrichment factor of 10 times higher, it has a concentration efficiency of 12 h-1 and it has a consumptive index of 12 mL. The analysis that was obtained in Cidurian River, West Java, Indonesia are 38.28 g.L-1 for Cr(III) and 26.73 g.L-1 for Cr(VI), while the accuracy are 98.84 % for Cr(III), and 100.73 % for Cr(VI).

Immobilized biocatalytic process development and potential application in membrane separation: a review.

Biocatalytic membrane reactors have been widely used in different industries including food, fine chemicals, biological, biomedical, pharmaceuticals, environmental treatment and so on. This article gives an overview of the different immobilized enzymatic processes and their advantages over the conventional chemical catalysts. The application of a membrane bioreactor (MBR) reduces the energy consumption, and system size, in line with process intensification. The performances of MBR are considerably influenced by substrate concentration, immobilized matrix material, types of immobilization and the type of reactor. Advantages of a membrane associated bioreactor over a free-enzyme biochemical reaction, and a packed bed reactor are, large surface area of immobilization matrix, reuse of enzymes, better product recovery along with heterogeneous reactions, and continuous operation of the reactor. The present research work highlights immobilization techniques, reactor setup, enzyme stability under immobilized conditions, the hydrodynamics of MBR, and its application, particularly, in the field of sugar, starch, drinks, milk, pharmaceutical industries and energy generation.