GC-MS approaches reported for 13C-MFA with relative derivatization methods and instrument characteristics for different target compoundsa.
| Instrument | Column | Oven temperature | Derivatizing agent | Target compounds | Ref. |
|---|---|---|---|---|---|
| Thermo-Quest ion trap GC-MS, mass tandem (70 eV) | DB5 ms (30 m × 0.25 mm × 0.25 μm) | T = 150 °C; increased by 3 °C min−1 to 180 °C, followed by a ramp of 40 °C min−1 to 260 °C | Dimethyl formamide dimethyl acetal (methyl 8) | Glutamate, citric acid cycle metabolites | 40 |
| HP6890 GC with GC/C III interface with a Ni/Cu/Pt combustion reactor and MAT 253 gas isotope MS (77 eV) | DB1 (60 m × 0.25 mm × 0.1 μm) | T = 120 °C for 5 min; increased by 5 °C min−1 to 280 °C, followed by a ramp of 20°C min−1 to 310 °C and kept isotherm for 5 min | 100 μL of MBDSTFA (80 °C for 60 min) | Proteinogenic amino acid | 41 and 75 |
| Agilent GC 7890B connected to a MS single quadrupole 5977A (EI-70 eV) | DB-5 ms (30 m × 0.25 mm × 0.25 μm) | T = 80 °C for 2 min, increased by 7 °C min−1 to 280 °C, hold for 20 min | 35 μL of pyridine and 50 μL of MTBSTFA + 1% (wt/wt) TBDMSClS (60 °C for 30 min) | Amino acids | 43 |
| 50 μL of 2% (wt/vol) hydroxylamine hydrochloride in pyridine (90 °C for 1 h). Then add 100 μL of propionic anhydride (60 °C for 30 min) | Carbohydrates | ||||
| 1 mL MeOH and 50 μL of concentrated sulfuric acid (100 °C for 2 h). Add 1.5 mL of DI water and 3 mL of hexane. Centrifuge, separate phases, evaporate to dryness and dissolve in 100 μL of hexane | FAMEs | ||||
| GC connected to an HP5971 MSD operating under ionization by electron impact at 70 eV | DB-XLB (60 m × 0.25 mm × 0.25 μm) | T = 100 °C for 5 min, increased by 10 °C min−1 to 300 °C and hold for 5 min | 70 μL of MTBSTFA (70 °C f or 30 min) | Organic and amino acids | 34 |
| GC 6890 connected to MS 5973 | DB5 column | ns | 100 μL THF and 100 μL MTBSTFA (70 °C for 1 h) | Amino acids | 61 |
| GC 7890B connected to MS 5875A, Agilent | HP-5-MS (30 m × 0.25 mm × 0.25 μm) | ns | 0.1% pyridine in MBDSTFA | Amino acids | 57 |
| Agilent 5973 inert MSD benchtop quadrupole mass spectrometer | DB5 ms column (60 m × 0.25 mm × 0.25 μm) | T = 100 °C for 4 min, increased by 5 °C min−1 to 200 °C, then by 10 °C min−1 to 300 °C, and held at 300 °C for 10 min | MTBSTFA at 25 °C for 30 min, then at 120 °C for 1 h | Amino acids and organic acids | 59 |
| Agilent 6890 GC connected to Agilent 5975B MS (EI 70 eV) | DB-35 MS capillary column | T = 100 °C for 3 min, increased by 3.5 °C min−1 to 300 °C | 60 μL of 2% methoxyamine hydrochloride in pyridine at 37 °C for 2 h, then 90 μL MBTSTFA + 1% TBDMCS at 55 °C for 60 min | Central carbon metabolism | 35 |
| Agilent 6890 gas chromatograph coupled to an Agilent 5973 quadruple MS | Equity®-1701 (15 m, 0.25 mm i.d., 0.25 μm film) | T = 75 °C for 1 min. increased by 40 °C min−1 to 165 °C, then by 4 °C min−1 to 190 °C and then 40 °C min−1 to 240 °C. At the end, temperature was increased by 4 °C min−1 to 260 °C and held constant for 4 min | 55 μL ECF | Proteinogenic amino acid | 37 |
a
Central metabolism = glycolysis, tricarboxylic acid cycle (TCA) or citric acid cycle (CAC) or Krebs cycle, pentose phosphate pathway (PPP); THF = tetrahydrofuran; MTBSTFA = N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide; FAME = fatty acids methyl ester; t-BDMS = t-butyldimethylsilyl; ECF = N-ethoxycarbonyl-amino ethyl-esters.