Articles | Volume 11, issue 1
Hydrol. Earth Syst. Sci., 11, 294–300, 2007
https://doi.org/10.5194/hess-11-294-2007

Special issue: A view from the watershed revisited

Hydrol. Earth Syst. Sci., 11, 294–300, 2007
https://doi.org/10.5194/hess-11-294-2007

  17 Jan 2007

17 Jan 2007

Determination of bromide, chloride, fluoride, nitrate and sulphate by ion chromatography: comparisons of methodologies for rainfall, cloud water and river waters at the Plynlimon catchments of mid-Wales

M. Neal, C. Neal, H. Wickham, and S. Harman M. Neal et al.

Abstract. The results of determination of bromide, chloride, fluoride, nitrate and sulphate using ion chromatography (IC) are compared with those obtained by colorimetric and inductively coupled plasma optical emission spectroscopy (ICPOES) for rainfall, cloud water and stream waters in the Plynlimon experimental catchments of mid-Wales. For bromide, the concentrations determined by IC are lower than those for the colorimetric method used; the colorimetric method probably determined bromide plus organo-bromine compounds. It is suggested that the values determined by the colorimetric method be termed dissolved labile bromine (DLBr). The study shows that sulphate is the overriding form of sulphur in the waters. For chloride and nitrate, measurements by both methods approach a 1:1 relationship that is barely statistically significantly different from unity. For fluoride, the IC method gives lower values than the colorimetric, especially for the stream waters. However, the colorimetric method determines total fluorine so that a difference is to be expected (for example, fluoride strongly complexes with aluminium that is present, especially in the streamwater).