A previous study on the determination of carbon, nitrogen, and phosphorus in cattail using cold neutron prompt gamma activation
analysis (CNPGAA) demonstrates that the results of numerous cattail samples showed favorable comparison to results from an
elemental analyzer (EA) for C and N. However, the results for P overestimated the results from a UV-VIS spectrophotometer
because of the interference of chlorine existing in cattail collected from an estuarine environment. To compare to CNPGAA,
a method for the determination of C, N, and P in cattail using thermal neutron prompt gamma activation analysis (TNPGAA) has
been developed in the TNPGAA facility at the National Institute of Standards and Technology (NIST) and evaluated through the
analysis of standard reference materials (SRMs).