i want to ask if it exists simple protocol to quantify Na+, K+,Ca2+ and Cl- , in plant tissues (root or leaf) without using Photoelectric flame photometer ?..just using UV Visible Spectrophotometer ..and if it is not possible why ? Thanks .
The only method I know to measure an ion in an spectrophotometer is the Ferrycianide method, and that is for Cl- only.
If you want to measure a number of cations and anions simultenously, the best choice would be ion HPLC, atomic absorption spectrometry or inductively
coupled plasma (ICP)–atomic emission spectrometry. You can measure Li, NH4, Na, k, Mg and Ca in one run and up to 11 anions depending the column or system configuration.
After mineralization (with H2O + H2O2 + HNO3), it is possible to quantify Cl- and Ca2+ by Patton-Reeder (calcon) indicator and titration (with AgNO3) methods, respectively.