Over the years, separation resolution and reduction of analysis time has continually improved in High Performance Liquid Chromatography (HPLC). For further improvement, column efficiency must be increased. The relationship among separation efficiency, the mobile phase linear velocity and particle size was investigated in detail in the early 1970 s [1]. This and other systematic investigations h...

A new simple, sensitive and precise green analytical procedure using an automated packed-reactor derivatization technique coupled with on-line solid-phase enrichment (SPEn) has been developed and evaluated to determine trace levels of methotrexate (MTX). The method was based on injection of MTX into a flowing stream of phosphate buffer (0.04 M, pH 3.4), carried through the packed oxidant reacto...

Modeling transfer phenomena in several chemical engineering operations leads to the resolution of partial differential equations systems. According to the complexity of the operations mechanisms, the equations present a nonlinear form and analytical solution became difficult, we have then to use numerical methods which are based on approximations in order to transform a differential system to a...