Polybrominated diphenyl ethers by HRGC/HRMS Coreen Hamilton Brian Fowler Louis Haviland Axys Analytical Services, Ltd.
PBDE - Introduction Method Outline Samples are spiked with 13 C 12 -labeled PBDE analogues;Samples are spiked with 13 C 12 -labeled PBDE analogues; Solvent extraction procedure;Solvent extraction procedure; Liquid chromatography clean-up;Liquid chromatography clean-up; Analyzed by high-resolution GC/MS;Analyzed by high-resolution GC/MS;
Method Flowchart SoxhletOrSoxhlet/ Dean Stark Soxhlet SolventSoxhlet Lipid Analysis (Y/N) Sample Extraction Solid Tissue, Blood XADWater Liquid Chromatography Clean-up Analysis by HR GC/MS
MS Method Overview Typical Calibration Concentrations (pg/ L) Analyte group CS-1CS-2CS-3CS-4CS-5 Natives PBDE Labelled C 12 PBDE
Calibration Analytes Homologue Group Target Congeners SurrogatesMono-PBDE’s PBDE 2 PBDE 3 Di-PBDE’s PBDE 8 PBDE 15 Tri-PBDE’s PBDE 17, 28 PBDE 28 Tetra-PBDE’s PBDE 47, 66, 75 Penta-PBDE’s PBDE 85, 99, 100 Hexa-PBDE’s PBDE 138, 153, 154 Hepta-PBDE’s PBDE 183, 190 Deca-PBDE’s PBDE 209
Detection LimitsMATRIX--> Analyte:Solidpg/gTissuepg/gWaterpg/LAirpg/sampleProceduralBlankLevelpg/sampleMono-PBDE <2000 Di- to Penta-PBDE <50 Hexa-PBDE222020<100 Hepta-PBDE555050<200 Nona-PBDE <500 Deca-PBDE <1000 Sample Size 10g10g1.0L 1 smpl Final Vol. ( L) Matrix Spiking, pg (PBDE 209) 2460 (17540)
Quantification and Identification PARAMETERSpecification RETENTION TIME WINDOW Natives must elute within 3 seconds of matching labelled surrogate. Other natives must elute within 6 seconds of predicted value from cal run RELATIVE ABUNDANCE Quant. And conf. Ions are within 15% of theoretical values PEAK CENTROIDS Quant. And conf. Ions coincide within 2 seconds
Quantification and Identification QC PARAMETER Specification ANALYSIS DUPLICATE Difference in native concentrations between duplicate samples <40%. PROCEDURAL BLANK Matrix Dependent (Previous Slide) MATRIX SPIKE RECOVERY 50 – 150% SURROGATE STD RECOVERY % for all labelled surrogates, except 13 C 12 PBDE 209 (25-400%)
RRF CONTINUING CAL VER ±35% of the actual for all natives ±50% of actual for all labelled surrogates except 13 C 12 PBDE 209 ( %) BRACKETING CAL <25% difference between opening and closing cal ver ’ s CHROMATOGRAM QUALITY peak tailing ratio of 13 C-DPE 77 peak (baseline peak width back half:front half) <3 Quantification and Identification
Instrument Sensitivity INSTRUMENT SENSITIVITY S:N > 3:1 for 7.5 pg of mono – hepta BDPE and 52 pg pf PBDE 209 injected, with ion ratios within specification. INSTRUMENT LINEARITY RSD of the RRF ’ s <25% for all native and labelled compounds except 13 C 12 PBDE 209 < 100%.
GC/MS Operating Conditions Source temp: 300 C Injector Temp: 300 C Electron Energy 35 eV Injector: Split/splitless at 300 C; 2 min splitless Trap Current: Variable Injection Volume 1.0 µ L Mass Resolution Final Sample Volume 22 µ L Carrier Gas 5000 Detector Voltage: eV Temperature Program: 100 C, hold for 3 min., 5C /min. to 320 C, hold for 5 min. Total run time 52 min.
All homologues analyzed in a single run;All homologues analyzed in a single run; Issues of PBDE-209 breakdown in DB-5 column (30m);Issues of PBDE-209 breakdown in DB-5 column (30m); Shorter column showed no improvement;Shorter column showed no improvement; Use of parent ions to reduce interference from PCB’sUse of parent ions to reduce interference from PCB’s GC/MS Conditions/Considerations
Advantages/Challenges Stability issues with PBDE-209;Stability issues with PBDE-209; Solubility of standards in weaker solvent (nonane vs. toluene);Solubility of standards in weaker solvent (nonane vs. toluene); Linearity of 209;Linearity of 209;