Simple extraction procedure for free amino acids determination in selected gluten-free flour samples

The simple extraction of flours samples followed by free amino acids determination procedures was studied and optimised. The conditions of amino acids derivatisation reaction with ninhydrin for chromatographic determination of free amino acids sum was discussed. The developed method was processed in terms of linearity, precision, accuracy, and limits of detection and quantification. Moreover, capillary isotachophoresis and HPLC methods were applied for individual free amino acids determination. The proposed extraction procedure is simple, fast and convenient for different flours samples. Studied procedures were used for free amino acids determination in twelve gluten-free flour samples (corn, oat, soy, rice, pumpkin, millet, peanut, hemp seed, buckwheat, amaranth, pea and chickpea) and the obtained results were compared with wheat flour.

On a separation voltage polarity switching transient capillary isotachophoresis method for higher sample loading capacity and better separation performance

Mechanism of a PS-tCITP method with higher sample loading capacity and better separation performance.

Development of an extraction procedure and analysis of electrostatically stabilized silanates from aqueous solutions

The analyzed organosilicon derivatives of electrostatically stabilized silanates belong to a group of pentacoordinated compounds. These derivatives are: 1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at, 1-(N-morpholiniomethyl)spirobi(1-sila-2,5-dioxa-4-methylcyclopentan-3-on)at, 1-(N-morpholiniomethyl) spirobi(1-sila-2,5-dioxa-4-(i-propyl)cyclopentan-3-on)at.In the course of the work, the extraction process and optimization of conditions for separation and determination of a mixture of electrostatically stabilized silanates were carried out using capillary isotachophoresis. Proper leading electrolytes were elaborated developed and the terminating electrolyte: 4,4’-bis[(1-morpholiniomethyl)spirobi(1-sila-2,5-dioxacyclopentan-3-on)at] was proposed. The extraction process involved the use of three stationary phases: octadecyl, octyl and phenylpropyl. The highest recovery values, approx. 94%, were obtained on the phenylpropyl column. The optimum time of analysis by the isotachophoretic technique did not exceed 12 min. The developed method of separation and determination of electrostatically stabilized silanates expands the possibility of research on biological activity of this group of compounds in aqueous solutions and surface water vegetation.

A separation voltage polarity switching method for higher sample loading capacity and better separation resolution in transient capillary isotachophoresis separation

Higher sample loading capacity and better separation resolution achieved by applying a voltage polarity switching method in transient capillary isotachophoresis separation.