Method I in this standard specifies the determination methods for polychlorinated biphenyls (PCBs), including indicator PCBs (PCB28, PCB52, PCB101, PCB118, PCB138, PCB153 and PCB180) as well as PCB18, PCB33, PCB44, PCB70, PCB105, PCB128, PCB170, PCB187, PCB194, PCB195, PCB199 and PCB206 in foods specified in the Global Environmental Monitoring System/Food Planning Part. Method II specifies the determination methods of PCB28, PCB52, PCB101, PCB118, PCB138, PCB153 and PCB180.
This standard is applicable to the determination of indicator PCBs in animal-based foods (like fish, shellfish, egg, meat, milk and their products) and oil and fat samples.
Method I Stable Isotope Diluted Gas Chromatography-mass Spectrometry
2 Principle
Adopt stable isotope dilution technology; add 13C12 labeled PCBs in the sample as the quantitative standard; carry out Soxhlet extraction; carry out chromatography purification, separation and concentration for the extracted sample solution with column chromatography, and then add it into the internal recovery standard; adopt gas chromatography - low-resolution gas chromatograph-mass spectrometer, analyze through quadrupole mass spectrum selected ion monitoring (SIM) or ion trap tandem mass spectrum multi-response monitoring (MRM), and then quantify through internal standard method.
3 Reagents and Materials
3.1 Reagents
3.1.1 N-hexane (C6H14): pesticide residue.
Foreword I 1 Scope Method I Stable Isotope Diluted Gas Chromatography-mass Spectrometry 2 Principle 3 Reagents and Materials 4 Instruments and Equipment 5 Analytical Procedure 6 Quality Control and Assurance 7 Others Method II Gas-chromatographic Method 8 Principle 9 Reagents and Materials 10 Instruments and Equipment 11 Analysis Procedure 12 Determination 13 Precision 14 Others Appendix A Standard Solution for Indicator Polychlorinated Biphenyl Appendix B Characteristic Ion and Isotopic Abundance Ratio Appendix C PCBs Mass Chromatogram and Mass Spectrogram through GC-MS Determination Appendix D Purification Flow Diagram
