Yes. Solid samples such as grain can be tested for phytic acid using Phytic Acid (Total Phosphorus) Assay Kit .
For solid samples, perform step 1 of the Sample Extraction using the following modification:
1. Accurately weigh approximately 1 g of sample material into a 75 mL glass
beaker. Add 20 mL of hydrochloric acid (0.66 M) and homogenise the sample using
a standard laboratory homogeniser or mortar and pestle, cover the beaker with
foil and stir vigorously for a minimum of 3 hours at room temperature
(preferably overnight for convenience). Follow the full Standard Assay
Procedure as described in the K-PHYT data booklet from step 2 of the Sample
mill cereal, plant or food product to pass a 0.5 mm screen, then follow the full Standard Assay Procedure as described in the K-PHYT data booklet from step 1 of the Sample Extraction procedure.