Enhanced Preservation of Volatile Organic Compounds in Soil With Sodium Bisulfate

摘要

Sodium bisulfate (NaHSO4) was evaluated as a means of chemically preserving soilsamples to prevent the microbiological degradation of volatile organic compounds (VOCs). Laboratory sample treatment consisted of spiking soil samples held in glass ampoules with aqueous solutions containing eight different VOCs or gasoline and then sealing them to eliminate volatilization as a concern. Samples preserved with NaHSO4 were held at room temperature (22 deg C), while equal numbers of unpreserved samples were stored refrigerated (4 deg C) and at room temperature. Results show that concentrations of all of the halogenated hydrocarbons tested remain fairly constant, independent of temperature or preservation. In contrast, all the aromatic hydrocarbons tested as separate analytes, or ones that could easily be identified in gasoline, experienced a complete (>95%) loss when held for nine days at room temperature. NaHSO4 preservation is one way of effectively eliminating biodegradation of VOCs in soil samples intended for low level (<1-microgram/g) analysis. jg.