Determination of Polychlorinated Biphenyls in Soil and Sediment
Analyze the polychlorinated biphenyls (PCBs) mixture standard using a gas chromatography-mass spectrometry (GC-MS) system. Perform qualitative analysis via Scan mode based on retention time, mass spectra, and characteristic ion pairs. Quantify using the external standard method in SIM mode. Once the method is established, analyze samples using SIM mode for qualitative identification based on peak retention times and characteristic ion ratios, and quantify using the external standard method.
Instruments and Experimental Conditions
AnYiPu 7700
Injection mode: Splitless;
Injection volume: 1.0μL;
Injection port: 270°C;
Column: HP-5MS 30m × 0.25mm × 0.25µm, Constant Flow Mode. Column Flow Rate: 1mL/min
Column oven temperature program: 40°C (0 min) 20°C/min 220°C (4 min) 20°C/min280°C (2 min)
Ion source: 270°C; Transfer line: 280°C; Solvent delay: 5 min;
Scan Mode: Full Scan (SCAN) and Selected Ion Monitoring (SIM); SCAN mode scan range: 45~450 amu.
Experimental Results
Prepare a standard solution at concentration 200ng/L, run on the instrument, inject 6 times. Figure 1 shows the total ion chromatogram for injection 6.
Overlay results.
Prepare standard samples with concentrations of 10ng/L, 20 ng/L, 50 ng/L, 100 ng/L, 200 ng/L, and 500 ng/L for instrument analysis.
Measurements yielded calibration curves for each compound; the linear relationship plots are shown below, with all correlation coefficients exceeding 0.995.
This study established a method for polychlorinated biphenyls in soil and sediment using gas chromatography-mass spectrometry (GC-MS).
The detection method demonstrates a well-defined linear relationship in the calibration curve. 6 consecutive injections show good repeatability in retention time and relative standard deviation of peak area.
Deviation is 0.5%~3.05%, indicating excellent instrument stability.