I'm interested to know if anyone else has developed a lab method for the analysis of free moisture in milled trona. One of our vendors uses a method that calls for weighing the sample before and after warming it up in a microwave for ~5 minutes on low. The concern is that trona is hygroscopic and will absorb water out of humid air in the time it takes to transfer the sample from the microwave to the scale. First question: is this concern valid? Second: would a computrac type of device be better suited for the analysis? Any thoughts? ■