Determination of Fluid Inclusion Electrolytes by Atomic Absorption Spectroscopy as of the Water Leachates of Crushed or Decrepitated Quartz Samples from Madan,Bulgaria

Two methods of opening fluid inclusions in hydrothermal quartz from Madan (Bulgaria) – mechanical (crushing) and thermal (decrepitation), followed by water leaching of the released components – were applied and compared. Problems concerning the sample preparation procedure, such as choice of an optimal sample mass and grain fraction, contamination of the grain surfaces, as well as the influence of La³⁺ and Cs⁺ additions on the water leaches etc., are discussed. The mol ratios X/Na (X=K, Ca, Mg, Mn) were determined by flame or electrothermal vaporization AAS of the dilute solutions obtained. The total salinity of inclusion fluid estimated by classical microcryometry is used to calculate the total concentrations of the main ions (Na⁺, K⁺, Ca²⁺, Mg²⁺ and Mn²⁺) in the water phase of the inclusions. Furthermore, the maximum concentrations of Pb²⁺ and Cu²⁺ were evaluated.