The Effect of Storage on the Radiocarbon, Stable Carbon and Nitrogen Isotopic Signatures and Concentrations of Riverine DOM

摘要: Chemical preservatives (e.g. mercuric chloride) are routinely added to freshwater samples prevent biological activity compromising the isotopic signature of dissolved organic matter (DOM) with time. However, alternative preservation methods needed due regulations restricting use potentially adverse environmental and health impacts, rendering such additions unviable. This study investigates whether a non-chemical storage method is sufficient maintain radiocarbon stable carbon nitrogen signatures DOM from low order river system draining peaty catchment. Some 50 L stream water were collected in 1 plastic carbuoy and, within 24 hr, 1-L aliquots transferred acid-washed bottles. Five analyzed immediately determine baseline values for 14C (pMC), δ13C (VPDB‰), δ15N (AIR‰), %C (mg L-1), %N L-1). Of remaining subsamples, 20 frozen further refrigerated at <4 °C. After 7, 30, 90, 180 days, 5 same manner as aliquots. Analysis results shows that there no statistically significant interaction between variables or length any determinants. Storage has effect on (pMC) [C] Length [N] L-1) values. Neither nor appear have (AIR‰)