There are those of us who develop assays for a variety of analytes. There are a couple of options for zinc. One is a fluorogenic agent which is a derivative of NBD. It's fluorescence changes upon binding of Zn++ to the agent. It's useful in the range of 0-5 nmoles of zinc. Another option is a colorimetric assay in which Zn binding to 5-Br-PAPS results in an increase in color at 560 nm.
Yurii V Geletii , there is no need to be so snobby and arrogant torwards people who needs technical solution. At least, it is out of ethics. Poguglite, chto takoe nauchnaya etika, espescially in discussions. I'm not your close relative for allowing you to answer me in such manner.