MULTI-PREP® GRAVITY SERIES GVSA-200 METHOD FOR THE ANALYSIS OF METHYLMALONIC ACID
IN SERUM OR URINE USING GC-MS
SAMPLE PREPARATION:
1. 500 µL sample and/or control plus 50 µL of a 50 nano moles
MMA- D3 /ml (in ethanol) internal standard is added to 13x100 mm test
tubes.
2. 1 mL of .001M NaOH in water is added to each tube.
3. All tubes are vortex mixed.
Note: If liquids do not elute freely by gravity flow, there is probably
air trapped within the column bed or frits .Tapping the column mounting
plate onto the vacuum box should initiate flow.
STANDARD PREPARATION:
1. A standard curve of MMA is prepared in 13x100mm test tubes as follows:
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* 1.18mg/L = 10,000 NM/L |
2. 50 µL of a 50 nano moles MMA- D3 /ml (in ethanol) internal standard is added to each tube.
3.Dry at 60° - 70° C under Nitrogen or Argon.
SAMPLE ELUTION 1. Elute with 2.0 mL 5M Acetic Acid in Methanol into screw cap tubes with Teflon lined cap.
2. Dry at 60° - 70° C under Nitrogen or Argon. Remove from heat as soon as eluates have dried.
1. Add 75 uL Acetonitrile and 25 uL MTBSTFA to each dried eluate and
vortex mix.
2. Incubate at 70° C for 30 minutes.
3. Vortex mix for 30 seconds followed by an additional 5 minutes of sonication
or vortex mixing.
Wash each column sequentially with the following solutions, allowing each wash to drain through the column by gravity flow.
1. 1 Methanol
2. 1 mL H2O
Assisted flow parameters may be set as follows:
Column Conditioning - Pass through column in approximately 20 seconds
(± 20%).
Sample, Sample Washes, and Elution Solvent - Pass through column in approximately
60 seconds (± 20%).
SAMPLE EXTRACTION AND PURIFICATION:
1. Pour prepared samples onto the columns and allow them to drain by
gravity flow.
2. Rinse empty tubes with 1 mL H2O and transfer wash onto column.
3. Wash each column 2 mL of 0.001M NaOH in H2O.
4. Wash each column with 2 mL of 0.6 M Acetic Acid in Methanol.
