LC-MS Applications for Environmental Analysis

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Figure 3. Mean GC-MS/MS results for routine laboratory QC samples for the in-house PCDD/Fs method over 3 routine batches of samples. This is plotted as
difference to result obtained on the GC-HRMS system.The QCs include a precision and recovery standard (PAR), Incinerator fly ash certified reference material
(CRM 490) and a sediment certified reference material (SETOC 738).
Quality Control in Routine Sample Batches
To evaluate the quantitative performance of the TSQ
Quantum XLS Ultra when applied to analytical quality
control samples, data was taken and compared with that
obtained on currently implemented GC-HRMS systems
(see Figure 3). These quality control samples included
certified reference materials (CRMs) for sediments SETOC
738 and CRM 490 incinerator fly ash. These were all
processed through the entire method procedure which
included accelerated sample extraction. All of the
compound recovery QC criteria specified in EPA 1613
and EN1948 were satisfied. This gave confidence that the
extraction yielded high recoveries throughout the study.
CRM 490 is a highly contaminated incinerator fly ash.
This type of sample and level of contamination allows for
a great opportunity for interference to occur. The MS/MS
system measured consistently higher concentrations for
TCDD/F and some penta and hexa furans. This was
indeed closer to the true CRM consensus value, so the
QC check passed.
SETOC 738 is a sediment CRM sample that is much lower
level CRM and had good agreement in the calculated
concentrations between the GC-MS/MS and HRMS data.
The GC-MS/MS data on these three types of QC sample all
fell within acceptable performance limits for the current
methodology suggesting that the selectivity and quantitative
performance of the technique is applicable for reporting
PCDD/F data in the routine environmental lab.
% Deviation from HRMS Result
50
0
-50
2378-TCDF2378-TCDD12378-PeCDF23478-PeCDF12378-PeCDD123478-HxCDF123678-HxCDF234678-HxCDD123478-HxCDD123678-HxCDD123789-HxCDD123789-HxCDF1234678-HpCDF1234678-HpCDD1234789-HpCDF
OCDD OCDF
Par CRM 490 SETOC 738