Soluble tungsten and molybdenum are available in soil mainly as their oxosalts, tungstate and molybdate. Tungstate is rather a hazardous compound, which may interfere with plant growth. Molybdate, on the other hand, is a required micronutrient, required e.g. for nitrate fixation in legumes. Both can easily be determined after alkaline digestion with ion chromatography followed by conductivity detection after chemical suppression.