Ash and Fiber content

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Safety measures

  • When preparing the Sulfuric acid - to do it the chemical hood (with lowered glass) with safety glasses and thick gloves
  • Pour the acid into the methanol in cooled (with ice) bucket
  • The work should be conducted in chemical hood
  • When dealing with hot equipment and sulfuric acid - wear thick gloves


  • before working with the Gooch make sure the clean them in the dish washer, burn them in 600 degrees and after cooling collect the debris using vacuum
  • Heating sleeves
  • Analytical balance
  • Condensation system (with ice!!!)
  • Electric kettle
  • 250 ml flasks
  • Filtering flask
  • Büchner funnel
  • Rubber adapter between funnel and filtering flask
  • Filter paper that fits the funnel
  • Gooch (weight the gooch after drying)
  • Gloves for high temperatures
  • pH paper


  • NaOH (1.25%)
  • Sulfuric acid (1.25%)
  • Distilled water


  1. Weight ~1 gr of dry sample (after fat extraction; see Fat content) and place it in weighted 250 ml flask
  2. Heat the flask (low boiling) with Condensation system with 150 ml sulfuric acid (1.25%) for 1 hour
  3. Wash the material (when hot, with boiled distilled water) in vacuum system (place the material in the buchner funnel over filtering paper, wet the filter paper before starting) until reaching neutral pH (measure with pH paper)
  4. Place the material (with the filter paper) into flask and heat (with condensation system) with 150 ml NaOH (1.25%) for 1 hour
  5. Wash the material using gooch and filtering flask until reaching neutral pH
  6. Dry the gooch in 105 degrees over night and weight (the fiber and un-organic components)
  7. Burn the gooch in 600 degrees for two hours and weight (the un-organic components only)