This application note describes a complete method to rapidly and precisely determine residue levels of malachite green and leucomalachite green in fish with the new Agilent 6410 LC/MS triple quadrupole system. Using positive mode electrospray ionization (ESI+) and multiple reaction monitoring (MRM), qualification and quantification were accomplished without the traditional tedious PbO2 oxidation process. The LC/MS/MS method’s LOQ is 0.01 µg/Kg, which easily meets the import requirement of 2 µg/Kg set by Japan and the EU.
This document presents a complete method for rapidly and precisely determining residue levels of malachite green (MG) and leucomalachite green (LMG) in fish tissue. The method utilizes the Agilent 6410 LC/MS triple quadrupole system with positive mode electrospray ionization (ESI+) and multiple reaction monitoring (MRM). It eliminates the need for traditional post-column oxidation processes.
The application details the sample preparation procedure, including extraction with acetonitrile and cleanup with methylene chloride. It specifies the LC/MS/MS instrumental parameters, such as column dimensions, mobile phase composition, gradient elution, and specific MRM transition parameters for both compounds. The document reports a limit of quantification (LOQ) of 0.01 µg/Kg, which meets import requirements set by Japan and the EU.
| Limit of Quantification (LOQ) | 0.01 µg/Kg |
|---|---|
| Column Dimensions | 2.1 x 150 mm, 5 µm |
| Column Temperature | 40°C |
| Mobile Phase A | 10 mmol/L ammonium acetate (pH 4.5) |
| Mobile Phase B | Acetonitrile |
| Column Flow Rate | 0.3 mL/min |
| Injection Volume | 10 µL |
| Ionization Mode | ESI(+) |
| Capillary Voltage | 4000 V |
| Drying Gas Flow | 11 L/min |
| Gas Temperature | 350 °C |
| Collision Gas | Nitrogen |
The method's limit of quantification is 0.01 µg/Kg.
No, qualification and quantification are accomplished without the traditional tedious post-column oxidation process.
The analysis is performed using the Agilent 6410 LC/MS triple quadrupole system.