A new method using high performance liquid chromatography was developed to quickly measure the amounts of pendimethalin and metribuzin in a herbicide formulation. The researchers found that the method was accurate and precise, with detection limits of 0.03 mg/l for metribuzin and 0.04 mg/l for pendimethalin. The method showed good linearity and recovery rates, making it a reliable way to analyze these herbicides in the formulation.