APPLICATION OF NEAR-INFRARED REFLECTANCE SPECTROSCOPY IN THE MEASUREMENT OF CARBON, NITROGEN, AND PHOSPHORUS IN SESTON FROM OLIGOTROPHIC LAKES

The application of near-infrared spectroscopy (NIRS), widely used in t he agricultural, food, and pharmaceutical industries, is extended to t he measurement of C, N, and P in seston from oligotrophic lakes at the Experimental Lakes Area, northwestern Ontario. Seston from 150-mL ali quots of lake water from several depths in two lakes on one mid-June s ampling date was collected on Whatman GF/C filters and measured first by NIRS then analyzed by standard wet chemistry methods. Correlation b etween chemically measured and NIRS-predicted values gave coefficients of determination between 0.913 and 0.982. The rapid, low-cost, nonche mical, nondestructive, efficient analysis of C, N, and P in seston by NIRS is feasible.