Spring and surface water quality of Cyprus ophiolites

Streams, springs and borehole waters were sampled from 21 sites within the Troodos ophiolite area in mid-May 1985. These sites represent the major waters of the area as assessed previously by the Geological Survey of Cyprus (Pantazis, 1978). The sites were chosen and samplings undertaken with the help of Evangelos Makredes of the Geological Survey of Cyprus and advice from some of his colleagues. In the field, samples were filtered through 0.45 μM membrane filters and then stored for chemical analysis in glass and polypropylene bottles depending upon the type of analysis. pH was determined electrochemically in the field, using a combination electrode, at the time of sample collection, with minimum contact of the water sample with the atmosphere (to avoid equilibration with atmospheric carbon dioxide). On immediate return from the field, alkalinity was determined by acidimetric titration to a pH of about 4.0 and was calculated using the method of Neal (1988); reduced sulphur was also determined using an ion selective electrode. In the case of alkalinity and reduced sulphur, the samples collected were stored in filled bottles and the analyses were undertaken rapidly: in the former case, this ensured minimal equilibration with atmospheric carbon dioxide; in the latter case, it minimised both hydrogen sulphide degassing and atmospheric oxygen contamination.

Samples were returned to the UK for further chemical analysis (Neal et al., 1992 for information on analytical methodologies). This analysis comprised colorimetric methods for the major anions, bromide and total iodine (mainly iodide plus iodate). Analysis of the major cations, the trace metals and boron was undertaken by inductively coupled plasma optical emission spectroscopy. In the case of the metals, samples were stored in polypropylene bottles cleaned by pre-washing in 5% v/v analar grade hydrochloric acid followed by high purity water and the samples were preserved in 1% v/v high purity, aristar grade, nitric acid. For the anion determinations, samples were stored in high purity water-cleaned glass bottles prior to analysis.