Quality assurance for plant tissue analysis by ICP‐AES

Abstract

A survey of 12 service laboratories using ICP‐AES for routine plant analysis reveals a variety of sample preparation and instrument calibration procedures in use. With the continued growth of ICP applications in plant analysis laboratories, a need exists for inter‐laboratory quality control. The assurance of data quality among laboratories cannot be expected unless a standardization of preparation methods and calibration is accomplished. In the selection of a method for multi‐element determination on the same sample solution, the completeness of elemental release and sensitivity for some elements may have to be compromised. In addition to the above survey, 8 plant samples were sent to 5 ICP laboratories that handle large volumes of plant samples with each using different preparation and calibration methods. The results for 11 elements show that the best precision among laboratories was for P, Mg, Mn, Ca and K, and the poorest precision for Al, Zn, Fe, Na, Cu and B. The imprecision noted for some elements was presumed to be caused by the diversity of preparation and calibration methods. Quality control efforts taken by this laboratory will also be given.