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MB Sample ID: SA213617
| Local Sample ID: | NB_Plasma_EXT_C18_Pos_025 |
| Subject ID: | SU002324 |
| Subject Type: | Human |
| Subject Species: | Homo sapiens |
| Taxonomy ID: | 9606 |
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Sample Preparation:
| Sampleprep ID: | SP002330 |
| Sampleprep Summary: | A 50 µL aliquot of plasma was extracted adding 150 µL cold (-20 C) methanol containing as internal standard mixture of creatine (methyl-D3, 98%), vitamin B3 (D4, 98%), uracil (1,3-15N2, 98%), chenodeoxycholic acid (2,2,4,4-D4, 98%). After over-night protein precipitation, proteins were removed by centrifugation for 10 minutes at 14,000 x g and 4 °C. The supernatant was collected and stored at -80 °C until analysis when was adding to the samples a second internal standard mixture of L-alanine (13C3, 99%), chenodeoxycholic acid (2,2,4,4-D4, 98%), L-leucine (13C6, 99%), L-phenylalanine (13C6, 99%), L-tryptophan (13C11, 99%), L-tyrosine (13C6, 99%), caffeine (13C3, 99%). stearic acid, sodium salt (13C18, 98%), sodium benzoate (13C6, 99%). Quality control (QC) samples were prepared by mixing equal volumes of all the NB plasma samples. In addition, a procedural blank, used to monitor contamination acquired during all stages of sample preparation, and external quality control (EQC) samples were included in the study and were prepared in the same way as the study samples. To avoid bias due to instrument drift, the analytical study design involves analyzing the 99 samples in a randomized way, with 16 QC and 9 EQC inserted every 6 and 12 runs respectively to assess analytical precision. Subsequently, 18 identification runs and a procedural blank were analyzed. |
| Extract Storage: | -20℃ |
