Page 19 - Catalog Instruments and Supplies

SCP SCIENCE 19
Digestion & Evaporation Systems

Method Development Guide
HIGHLY REACTIVE samPLES

HIGHLY REACTIVE EXAMPLES Highly
i.e. Animal Feeds, Waste Oils*, Reactive
Samples
Polymers, Unknown Samples

* Not to be used with HNO3/HClO4

Choose Acid Combination

PlasmaPURE H2SO4 Acid PlasmaPURE H2SO4/HNO3 Acids
- Will oxidize, hydrate or sulfonate organic compounds - First add H2SO4 to char sample:
- Works best above 230°C
- Glass or Quartz sample tubes Sample should be above 200°C
- Then add HNO3 to digest the sample:
PlasmaPURE HCl Acid
- Strong non-oxidizing mineral acid Sample should be between 80°C and 120°C
- Sample should be below 80°C - Glass or Quartz sample tubes
- DigiTUBE, Glass, or Quartz sample tubes, Watch Glasses
PlasmaPURE HNO3/HClO4 (should always be used with
PlasmaPURE HNO3 Acid HNO3) Acids
- Strong oxidizing mineral acid - Very strong combination
- Sample digested between 80°C and 120°C
- DigiTUBE sample tubes, Watch Glasses - Sample should digest between 145°C and 200°C

PlasmaPURE HF Acid - DMiugsiTt UusBeEH, GCllaOs4s,fuomr eQhuoaordtz sample tubes, Watch Glasses
- Strong non-oxidizing acid -
- Ideal for samples such as SiO2
- Sample should digest below 95°C PlasmaPURE HNO3/HCl Acids
- Teflon® sample tubes - Very strong oxidizing media
- Reacts upon mixing - forms brown fumes upon mixing
- Samples should be digested between 95°C and 110°C
- DigiTUBE, Glass, or Quartz sample tubes, Watch Glasses

Below 180 °C Choose System Above 180 °C
DigiPREP MS, Jr. or LS, h, MINI & Choose Weight DigiPREP HT & Touch Screen Controller
Touch Screen Controller Use: "Time to Temperature"

Use: - Multiple "Time to Temperature" "Time at temperature"
- Multiple "Time at Temperature"
- DigiPROBE to control internal Select 100 ml or 250 ml tubes
sample temperature

Below 2 grams Above 2 grams
- Add 5 ml total acid at starting point - Add 10 ml total acid at starting point

- Always add acid in small aliquots - Always add acid in small aliquots

Digest Sample

NO Is Digestate clear?* * Not sole criteria for a complete digestion.

Is there precipitate? YES YES Is Digestate clear?*
YES NO
Digestion NO
NO Dilute the sample with water and Complete YES Review the initial acid
see if the precipitate remains. combination

Is the digestate clear, but acid Reduce the initial acid
concentration high? concentration