AnYiPu 7700 Single Quadrupole Gas Chromatography-Mass Spectrometry for the Determination of Pyrethroid Pesticides in Water
Refer to "HJ 753-2015 Determination of Cypermethrin and Pyrethroid Pesticides in Water by Gas Chromatography-Mass Spectrometry." Use a gas chromatography-mass spectrometer (GC-MS) to analyze pyrethroid pesticide mixtures. Qualitative analysis is performed using Scan mode based on retention time, mass spectra, and characteristic ion pairs. Quantification is conducted via external standard calibration in Sim mode. Once the method is established, samples are analyzed using Sim mode for qualitative identification based on peak retention times and characteristic ion ratios, with quantification performed using the external standard method.
Experimental Conditions
Injection mode: Pulsed splitless; Pulse pressure: 20 psi; Pulse time: 0.75min;
Purge flow: 50mL/min; Purge time: 1.0min; Injection volume: 1.0 μL; Injection port: 280 ℃;
Column: HP-5MS 30m × 0.25mm × 0.25µm
Column Flow: 1mL/min (Constant Flow Mode)
Column oven temperature program: 70°C (2 min) → 30°C/min to 220°C (3 min) → 5°C/min to 80°C (5 min)
20℃/min300℃ (5 min)
Ion source: 280°C; Transfer line: 300°C; Solvent delay: 5 min; Detector voltage: 900 V
Scan Mode: Full Scan (SCAN) and Selected Ion Monitoring (SIM); SCAN mode scan range: 45~550 amu.
Experimental Results
Analyze according to the instrumental analysis conditions, starting from low concentration to high concentration (Bifenthrin, Permethrin, Fenvalerate, Cyfluthrin).
The pyrethroid concentrations were 10ng/mL, 50 ng/mL, 100 ng/mL, 150 ng/mL, and 200 ng/mL. Lambda-cyhalothrin
The linear concentration points for esters, cypermethrin, fenvalerate, and deltamethrin are 0.1 μg/mL, 0.5 μg/mL, respectively.
1.0 μg/mL, 1.5 μg/mL, and 2.0 μg/mL), with target analyte concentration on the y-axis and target analyte response value (peak area) on the x-axis.
Plot the coordinates and fit a calibration curve using least squares; all correlation coefficients exceed 0.99.
Prepare samples at limit of detection (LOD) and limit of quantification (LOQ) concentrations using selected ion monitoring. Both LOD and LOQ are ≤ the national standard method detection limits, meeting requirements.
This study establishes a method for determining pyrethroid pesticides. The linearity, precision, and limit of detection all exceed national standard requirements, making the method suitable for pyrethroid analysis.