Comparison of gas and liquid chromatography for determination of anilazine in potatoes and tomatoes.

Anilazine (2,4-dichloro-6-(2-chloroanilino)-1,3,5-triazine), a triazine fungicide, is extracted from potatoes or tomatoes with acetonitrile. An aliquot of the filtered extract is partitioned between methylene chloride and water. The organic phase is concentrated and passed through a 3% deactivated Florisil column for cleanup. The eluted anilazine is then concentrated and determined by liquid chromatography (LC) on LiChrosorb RP-8 column with a mobile phase of acetonitrile--water (55 + 45) and detection at 275 nm, the absorption maximum of anilazine. Twenty-five nanograms produces a 5 cm peak under the conditions used. Detection limit is about 0.02 ppm in both vegetables. A comparison is made with gas chromatography, using either an electron capture (EC) or nitrogen--phosphorus alkali-flame ionization (NP) detector. Separations are carried out on a 4% SE-30 + 6% SP-2401 column at 195 degrees C at 40 mL/min. Detection limits for all systems studied are about 0.02--0.05 ppm in the samples studied. Recoveries over a concentration range of 0.2--10.0 ppm are greater than 80% with the extraction procedure employed and LC determination.