ABSTRACT
In order to automate sample preparation processes, a precision pattern dispenser was designed to reproducibly dispense radioactive solutions at pre-defined positions. It is composed of an automatic liquid sample handling unit coupled to an XYZ table. Qualification tests were conducted to evaluate the performance of the instrument and to assess the compliance with the requirements, in particular trueness (< 2%) and repeatability (< 1%). The instrument allows preparing sources in different source holders and on air filters, in a fast and accurate way.
ABSTRACT
This study investigates the importance of selected oil degradation components and some analogues in the formation of acrylamide. For this, a model system containing silica gel, PBS buffer, and oil was heated in a closed tubular reactor, under practically relevant heating conditions. Several probable acrylamide precursors were mixed together with free asparagine in the model system, such as partial glycerides, glycerol, acrolein, acrylic acid, and several aldehydes. Only the heated model system containing acrolein and asparagine showed a significantly higher acrylamide content compared to the control to which only asparagine was added. It was postulated that a nucleophilic 1,2-addition of the alpha-amino group of free asparagine to the carbonyl function of acrolein would lead to the formation of acrylamide. This hypothesis could partially be confirmed, replacing acrolein with other alpha,beta-unsaturated aldehydes. However, the contribution of acrolein to the overall formation of acrylamide appeared to be negligible in the presence of a reducing sugar, indicating that in foodstuffs the importance of acrolein and other oil degradation products is probably small.
