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Pros/Strengths
ER 1
The organizer took great effort setting up the procedures to allow for individual lab's choice of various instruments,
columns, SPE vendors, and evaporation techniques, as long as the lab passed the performance requirements. The
procedures are straight forward and not hard to follow.
ER 2
Fairly easy method that requires significantly less sample preparation compared to other methods. Utilizes equipment and
instrumentation that is widely available. Uses less flammable and toxic solvents than other methods. Sample handling is
minimized which decreases the probability of environmental contamination.
ER 3
Strengths include: 1. easy to follow criteria for sample preparation evaluation 2. easy to follow instructions for solution and
calibration solution preparation 3. some allowance for environmental background of the naphthalene 4. importance of
monitoring blank is clearly stated
ER 4
The method is simple, fast, accurate, robust and is easy to follow.
ER 5
Well written, encompasses analyses of PAH compounds deleterious to humans at low levels, the calculations outlines on
pages 14-15 are well written.
ER 6
A major strength is that the method is an isotope dilution (ID) GC-MS methods using C13 labeled internal standards for 13
of the 19 target PAHs. The sample preparation appears to be simplified compared to normal solvent extraction methods
(Soxhlet, ACE, MAE). Another strength is the performance criteria required for the choice of GC column and the
requirements to separate critical PAH isomers such as the benzofluoranthenes.
ER 7
The method is simple, fast, and easy to use. High sample throughput with little lab ware needed. Applicable to a variety of
seafood matrices. Overall method performance are acceptable.
ER 8
no comment
Cons/Weaknesses
ER 1
Isotope-Labeled mixed standards may be expensive or could be unavailable occasionally. Precision of results (all three
levels) may have some room for improvement.
ER 2
Still requires some sample clean up, including a dry down step which if performed incorrectly could cause artificially low
calculated concentrations for low molecular weight PAHs. Does not incorporate many alkyl homolog PAH compounds.
These are often present at higher concentration in oil contamination and have similar toxicity to the PAHs. Addition of
these compounds to the GC-MS method would increase the applicability and impact of the method. This could perhaps be
done in the future
ER 3
Weaknesses include: 1. Method scope of 1 ug/kg LOQ of BaP was not tested as a fortification level. As I read the method,
the lowest fortification level for BaP was 2 ug/kg. 2. Polypropylene tubes used for extraction will likely cause users of the
method issues with PAH contamination. Discussion of alternatives would be helpful. 3. PAH GC-MS analysis has significant
differences than typical analysis of most other types of compounds. Guidance for GC-MS parameters would likely be helpful
for users of the method. These include parameters like inlet temperature, transfer line temperature, ion source temperature,
column loadability and efficient flow conditions. 4. There is no recommendation on how to report data on chrysene and
triphenylene if the recommended, but not required, 50% valley separation is not met. Can chrysene and triphenylene be
reported together? 5. Ion ratios are mentioned as a requirement for identification but there is no indication as to the RSD
value that is acceptable or some other qualification. 6. When a linear calibration curve is not possible, allowance for a "well-
characterized" quadratic formula is made but with no discussion of what "well-characterized" means. Some guidance would
be useful because some user will not be accustomed using quadratic calibration curves.
ER 4
A commercially available mix of standards suitable for the method is beneficial.
ER 5
The Safety Section must be in the front of the method since safety is more important than any other part of the protocol.
Method must be more specific. Under Degradation Issues on page 18, the discussion emphasizes the need for a Stability
Study. 18.2 megaohm water should be used for any GC/MS method (page 9, Section C). Need a statement that
documented calibrations/reference checks were performed on all analytical equipment and instrumentation used in the
collaborative study.
ER 6
A major weakness is that there is no validation using a certified reference materials for PAHs in seafood. Standard Reference
Material (SRM) 1974b Mussel Tissue is mentioned as part of the qualification of the labs (p. 6) as a practice sample, but no
data are reported using SRM 1974b for validation of the proposed method. The availability of SRM 1974c (which has
replaced SRM 1974b) provided an excellent opportunity to use a CRM to validate an AOAC method. The use of only
fortified/spiked samples for the method validation is a weakness. Spiked samples are sometimes the only option but in this
ERP PROFILE SUMMARIES
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