3 A total of 18 samples was collected and then analysed for the isotopes mentioned earlier. 4 Samples 1–9 were collected in thoroughly-rinsed 25 ml brown glass bottles which were fi lled to the top and then sealed tightly to prevent contamination. 5 Th e fi lled bottles were shipped directly to two separate laboratories at Reading University, where they were analysed using standard methods suitably miniaturised to handle small quantities of water. 5
Chapter 48