Microsampling for Infrared and Emission Analyses
A commonly occurring problem which the analytical chemist faces is that of obtaining and transferring microamounts of sample. Many techniques are available for addressing this problem; however, they all entail the use of some type of carrier or transport media. Chlorinated solvents, which readily evaporate, are often used in it spectroscopy for this purpose and collodion may be used for the collecting of micro-samples in emission spectroscopy. Unfortunately the use of these materials may, at times, be of greater hindrance than help. For example, evaporating solvents may cause water to condense on the micro-sample which is not readily desorbed afterwards and the resultant infrared will give questionable absorption bands. Likewise with collodion for emission analyses, excess carrier at times will cause the sample to “pop” during the analysis and the sample will be lost. Other types of complications are occurring in the electronics industry where it is desired not to treat a contaminated part but just remove the contaminants for analysis. All these situations have led us to seek a means of collecting sample which is simple yet does not involve the use of transfer media.