Particles+Extraction Soong

Description and working steps

Preparation

• 600 ml 0.05M K₂SO₄
• Shaker, centrifuge
• 200 glass beads
• 900 ml 0.5% Na-HMP solution
• 2mm sieve, 63 um sieve
• 40 aluminum pans
• Bottles (50ml) for WSEOM

Day 1:

• Weigh out 6g of 2mm sieved oven dried soil into 50ml centrifuge tubes (record weights).
• Add exactly 30 ml of 0.05 M K₂SO₄
• Shake for 1 hr
• Centrifuge for 30 minutes at 1000g
• Pour off WSEOM fraction
• Freeze WSEOM fraction and eventually freeze dry
• Add 10 glass beads to non-soluble fraction and 30 ml 0.5% sodium-hexametaphosphate
• Shake on reciprocal shaker for 18 hrs
• Pre-weigh all pans
• Oven dry a sample of initial soil, to get moisture content

Day 2:

• Stack 2mm sieve over 63 um sieve over a pan
• Rinse sample over sieves, collect glass beads on 2mm sieve and POM fraction on 63 um sieve
• Pour POM fraction and MEOM fraction into pre-weighed aluminum pans
• Dry POM and MEOM in oven at 110 °C for 24 hours or until dry

Day 3-4:

• Weigh dry POM and MEOM fractions + pan
• Scrape out fractions into a storage container

Initial Aim

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Advantages

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Disadvantages

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References

The method is unpublished.