Metabolomics Workbench : NIH Data Repository

MB Sample ID: SA217526

Local Sample ID:	Blk_MQBlk_1
Subject ID:	SU002352
Subject Type:	Water sample

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Sample Preparation:

Sampleprep ID:	SP002358
Sampleprep Summary:	Each sample was extracted using a modified Bligh-Dyer extraction. Briefly, filters were cut up and put into 15 mL teflon centrifuge tubes containing a mixture of 100 µm and 400 µm silica beads. Heavy isotope-labeled internal standards were added along with ~2 mL of cold aqueous solvent (50:50 methanol:water) and ~3 mL of cold organic solvent (dichloromethane). The samples were shaken on a FastPrep-24 Homogenizer for 30 seconds and chilled in a -20 °C freezer repeatedly for three cycles of bead-beating and a total of 30 minutes of chilling. The organic and aqueous layers were separated by spinning samples in a centrifuge at 4,300 rpm for 2 minutes at 4 °C. The aqueous layer was removed to a new glass centrifuge tube. The remaining organic fraction was rinsed three more times with additions of 1 to 2 mL of 50:50 methanol:water. All aqueous rinses were combined for each sample and ~2 mL of cold dichloromethane was added to the combined aqueous layer. Tubes were shaken and centrifuged at 4,300 rpm for 2 minutes at 4°C. The aqueous layer was removed to a new glass vial and dried under N2 gas. The remaining organic layer in the bead beating tubes was transferred into the glass centrifuge tube and the bead beating tube was rinsed two more times with cold organic solvent. The combined organic rinses were centrifuged, transferred to a new glass vial, and dried under N2 gas. Dried aqueous fractions were re-dissolved in 380 µL of water. Dried organic fractions were re-dissolved in 400 µL of 90:10 methanol:toluene. 20 µL of isotope-labeled injection standards in water were added to the aqueous fractions. Blank filters were extracted alongside samples as methodological blanks.

Sampleprep ID:

SP002358

Sampleprep Summary:

Each sample was extracted using a modified Bligh-Dyer extraction. Briefly, filters were cut up and put into 15 mL teflon centrifuge tubes containing a mixture of 100 µm and 400 µm silica beads. Heavy isotope-labeled internal standards were added along with ~2 mL of cold aqueous solvent (50:50 methanol:water) and ~3 mL of cold organic solvent (dichloromethane). The samples were shaken on a FastPrep-24 Homogenizer for 30 seconds and chilled in a -20 °C freezer repeatedly for three cycles of bead-beating and a total of 30 minutes of chilling. The organic and aqueous layers were separated by spinning samples in a centrifuge at 4,300 rpm for 2 minutes at 4 °C. The aqueous layer was removed to a new glass centrifuge tube. The remaining organic fraction was rinsed three more times with additions of 1 to 2 mL of 50:50 methanol:water. All aqueous rinses were combined for each sample and ~2 mL of cold dichloromethane was added to the combined aqueous layer. Tubes were shaken and centrifuged at 4,300 rpm for 2 minutes at 4°C. The aqueous layer was removed to a new glass vial and dried under N2 gas. The remaining organic layer in the bead beating tubes was transferred into the glass centrifuge tube and the bead beating tube was rinsed two more times with cold organic solvent. The combined organic rinses were centrifuged, transferred to a new glass vial, and dried under N2 gas. Dried aqueous fractions were re-dissolved in 380 µL of water. Dried organic fractions were re-dissolved in 400 µL of 90:10 methanol:toluene. 20 µL of isotope-labeled injection standards in water were added to the aqueous fractions. Blank filters were extracted alongside samples as methodological blanks.