4 (1:3, w/v) at 0 [degrees]C and the samples were added to an equal volume of 10% metaphosphoric acid
San Diego, CA) and then subsampled, combined with 25% (w/v) metaphosphoric acid
(8 mL ruminal fluid to 2 mL acid) and frozen (-20[degrees]C) for volatile fatty acid and N[H.
Ascorbic acid was extracted using an acetic acid and metaphosphoric acid
For vitamin C analysis, aliquots of the heparin-plasma samples were stabilized with 60 g/L metaphosphoric acid
(1:1 by volume) before storage.
For ascorbic acid analysis, frozen leaf segments (1000 mg) were homogenized in 7 mL of 5% (w/v) metaphosphoric acid
with a Polytron (PT3000, Kinematia, AG, Littau, Switzerland) at a speed of 4000 g for 3 min and kept cooled with ice.
Red blood cell lysate precipitated with metaphosphoric acid
The solution was then put into a plastic bottle containing 1 ml of 25% metaphosphoric acid
and 1 ml of 0.
Similarly, TAA in frozen serum containing 50 g/L metaphosphoric acid
(MPA) degrades at no more than 1% of the total mass per year over a 2-year period when stored at -70 [degrees]C (9).
Frozen leaf segments (1 g) were homogenized in 7 mL of 5% metaphosphoric acid
with a Polytron (PT3000, Kinematia, AG, Littau, Switzerland) at a speed of 29 200 rpm for 3 min and kept cooled with ice.
For assessment of VFA concentrations and proportions, the filtrate (5 ml) was combined (5:1) with 25% (v/w) metaphosphoric acid
This sample was then mixed thoroughly with acid washed sand using metaphosphoric acid
(10 g of acid dissolved in 100 mL water) reagent, and transferred to a 100 mL graduated flask.
The first step in glutathione analysis is usually protein precipitation by acidification [trichloroacetic acid (TCA), perchloric acid, metaphosphoric acid
, or sulfosalicylic acid], yielding a clear, protein-free supernatant after centrifugation.