The invention relates to a method for detecting trace
manganese in an environmental sample, belonging to the field of a detection method of the environmental sample. The method comprises the steps of weighing 0.200g of environmental sample, and putting the environmental sample into a
quartz beaker; feeding 10mL of top-grade pure
nitric acid, and carrying out low-temperature
decomposition; when the color of
organic matter is changed into light yellow from brown, feeding 1mL of
perchloric acid into the
organic matter, and continuously decomposing until white
smoke is not produced and the solution is nearly dry; cooling, and then decomposing by 25mL of 1%
nitric acid; then, feeding 1mL of 5%
potassium periodate and 2mL of concentrated
nitric acid into the solution, heating and boiling; after reddish color appears, carrying out micro-boiling for 3 minutes; adjusting the pH value of the obtained solution to be 3, and pouring the solution into a conical flask, wherein 30mg of cross-linked
chitosan (CCTS) which is subjected to cross linking by
epichlorohydrin is contained in the conical flask; oscillating for 30 minutes on a constant temperature shaking table, and filtering; eluting the adsorbed CCTS subjected to cross-linking by
epichlorohydrin by 10 drops of 10%
hydroxylamine hydrochloride, and making up the volume to be 5ml; and measuring the content of
manganese by a
flame atomic absorption spectrometry. The method is simple, convenient, rapid, high in
repeatability and low in
detection limit, has an accurate result and has a relatively high practical value when being used for detecting the trace
manganese in the environmental sample.