Purdue University graduate student Santosh Soparawalla, left, and postdoctoral researcher Fatkhulla Tadjimukhamedov demonstrate a miniature mass spectrometer used to detect chemicals on store produce. Purdue News Service / Mark Simons A team of scientists at Purdue University is perfecting a portable device that can quickly detect both chemical residues and bacterial contamination on fresh fruits and vegetables without complicated laboratory analysis.     In a recent trial in a supermarket, university graduate students armed with the machine were able to identify oranges with residues of the fungicide benzimidazole and apples that had been treated with the scald inhibitor diphenylamine (DPA). The […]