Under optimized conditions, measurements of the diatomic molecules
NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at
404.722 nm allowed calibration curves to be constructed in the ranges 500–5000 mg L−1 N (r = 0.9994),
100–2000 mg L−1 P (r = 0.9946), and 100–2500 mg L−1 K (r = 0.9995)