Sample #38

Efflorescence from Espinhaco

Referring Sample: 10/17-9

Date: 25th December 2018

  1. weighed out 0.280g
  2. add 25ml DIW
  3. heat 95ºC on steam bath for 4 hrs
  4. filter through 103 (gravity) and wash x3 with DIW
  5. make up to 50ml => Water Soluble Fraction
  1. residue weighs 0.216g
  2. add 3ml HCl conc.
  3. add 1ml HNO3 conc
  4. cover & heat @ 250ºC on hotplate for 8 hrs
  5. uncover and evaporate to dryness
  6. add 25ml DIW
  7. add 4ml HCl conc
  8. heat at 70ºC on hotplate for 7 hrs
  9. filter through 103 (gravity)
  10. set aside filtrate
  11. repeat 2. to 9. for residue
  12. combine filtrates
  13. make up to 100ml => Aqua Regia Soluble Fraction
  1. residue weighs 0.020g
  2. mainly SiO2? – not processed further

Water soluble fraction and aqua regia soluble fraction analyses as per standard protocols for wall-wash samples.