Determination of Chlorine in Reference Materials of Marine Sediments of the OOPE and SDO Series by X-ray Fluorescence Spectrometry

Abstract

The main problem in determining chlorine in marine sediments is the lack of a sufficient number of reference materials (RMs) with certified values for the content of this element. In the RMs of the earlier SDO series (bottom sediment standards) and the newer OOPE series (pelagic sediment standards), chlorine contents in clays and silts are given only as informative values. A method for the X-ray fluorescence determination of chlorine in RMs of pelagic sedimentary deposits (clays and silts) of the SDO and OOPE series is proposed. The emitters were prepared by pressing the test material—previously thoroughly homogenized and dried at 105°C—with the addition of polystyrene as a binder. Calibration characteristics for chlorine determination were obtained using reference samples, the matrices of which were RM clay and silt samples washed free of chlorine, with calculated portions of NaCl powder added. The results of chlorine determination in the original clay and silt standards agree well with the informative values given in the RM certificates. The uncertainty of chlorine determination by the X-ray fluorescence method in clay and silt RMs within the concentration range of 2–4% is characterized by a standard deviation from 0.08 to 0.23%.