Low-level soluble chloride extraction in soil

Three methods of extraction of low-level soluble chloride contents from vadose-zone soil were evaluated in this study. Three methods were employed on a silty sand soil using a 2:1 fluid:soil ratio: 1) Method A utilized three successive rinses with deionized water; 2) Method B applied three successive rinses of 0.0001 M and 0.001 M Na(2)SO(4) solution; and 3) Method C passed deionized water through the soil with a pressurized filtration system three times. Method A had lower standard deviation and yielded more consistent soluble chloride contents per rinse than method C; Method B was ruled out because of concerns that the Na(2)SO(4) • Three successive rinses of soil with deionized water achieved consistent extraction results. • Multiple rinses are necessary to extract soluble chloride if chloride contents are low. • This method is amenable to analysis of soil in vadose-zone borehole samples.