31317382gas chromatographyPT2026-03-30 20:25:28UF31317383GCNDUF31317384chromatography, gasNDUF31317385gas chromatographic analysisNDBT31304416chromatographyPTNT31317454gas chromatography-mass spectrometryPTNT31341394pyrolysis gas chromatographyPTNT31341398capillary gas chromatographyPT