This document introduces a method for screening 12 plant growth regulators (PGRs) in grape samples using Agilent 6530 accurate-mass Q-TOF LC/MS system with Agilent 1290 Infinity LC. The method shows excellent sensitivity and outstanding mass accuracy.
This document presents a sensitive and effective method for screening 12 Plant Growth Regulators (PGRs) in grape samples using the Agilent 6530 Accurate-Mass Q-TOF LC/MS system coupled with the Agilent 1290 Infinity UHPLC. The method utilizes a simple, inexpensive dispersive C18 sample cleanup technique to remove background matrix, enabling the detection of multiclass PGRs with outstanding mass accuracy (less than 1 ppm for 50 ppb and 100 ppb concentrations).
The analysis involves liquid phase extraction followed by dispersive C18 cleanup, internal standard spiking, UHPLC gradient separation, and detection via Jetstream ESI-LC/MS/MS. The document details specific chromatographic conditions, mass spectrometer settings, and results for both positive and negative ion modes, demonstrating the system's capability to identify compounds using accurate mass and structural elucidation via MS/MS.
| Total run time (positive mode) | 16 min |
|---|---|
| Total run time (negative mode) | 6 min |
| Injection volume | 2 yL |
| Column temperature | 40 °C |
| Flow rate | 0.2 mL/min |
| Mass accuracy (50 ppb/100 ppb) | less than 1 ppm |
| Mass accuracy (5 ppb) | less than 5 ppm |
The PGRs detected in positive mode are Chlormequat, d4 chlormequat, Daminozide, Zeatin, Kinetin, 6-Benzyl adenine, Indol Butyric acid, Forchlorfenuron, and Paclobutrazol.
The PGRs detected in negative mode are Gibbrelic acid, Abscisic acid, and 2, 4 Dichlorphenoxy acetic acid.
The sample is prepared by adding a 5-g amount of homogenized grape sample to 40 mL Methanol: Water (80:20), mixing with C18 ODS SPE Bulk, vortexing, centrifuging, and diluting before injection.