AOAC 965.09

Nutrients (Minor) in Fertilizers: Atomic Absorption Spectrophotometric Method

Applicability: AOAC 965.09 is a classic Atomic Absorption Spectrophotometric Method for determining minor elements (nutrients) like Calcium, Copper, Iron, etc., in fertilizers, using sample preparation involving strong acids (HCl, HF, HClO4) and dry ashing for organic materials, primarily suited for older analytical techniques but serves as a benchmark for modern microwave digestion methods (like EPA 3052) in validating nutrient analysis in various materials, including organic fertilizers.

Purpose: The purpose of AOAC 965.09 is to provide a standardized, validated atomic absorption spectrophotometric method for determining minor nutrient elements (like Copper, Iron, Manganese, Zinc, Magnesium) in fertilizers, ensuring accurate quality control and regulatory compliance by measuring these essential micronutrients. It details the extraction and analysis process, originally using Atomic Absorption (AA) but often updated with newer technology like Inductively Coupled Plasma (ICP).