全氟烷基酸 快速 液相色谱法/串联质谱法分析增加样品通量

Raptor™ C18 SPP 5 µm core-shell silica particle columns
offer excellent resolution for fluorochemicals with short
total cycle times. For even faster analysis, 2.7 µm core-shell
particles are available.
• Meets EPA Method 537 requirements.
• Unique, robust Raptor™ C18 column design increases
instrument uptime.
Perfluorinated alkyl acids are man-made fluorochemicals
used as surface-active agents in the manufacture of a variety
of products, such as firefighting foams, coating additives,
textiles, and cleaning products. They have been detected in
the environment globally and are used in very large quantities around the world. These fluorochemicals are extremely
persistent and resistant to typical environmental degradation
processes. As a result, they are widely distributed across the
higher trophic levels and are found in soil, air, groundwater,
municipal refuse, and landfill leachates. The toxicity, mobility,
and bioaccumulation potential of perfluorooctanesulfonic
acid (PFOS) and perfluorooctanoic acid (PFOA), in particular,
pose potential adverse effects for the environment and human health.
Perfluorinated alkyl acid analysis can be challenging because
these compounds are chemically different from most other
environmental contaminants. They are difficult to quantify
because some are more volatile than others, and they also
tend to be more hydrophilic and somewhat reactive. In addition, fluorochemicals are present in polytetrafluoroethylene
(PTFE) materials, so excluding the use of any PTFE labware
throughout the sampling and analytical processes (including
HPLC solvent inlet tubing) is essential for accurate analysis.
Typically, perfluorinated alkyl acids are analyzed by LC-MS/
MS methods, such as EPA Method 537, but long analysis times
can significantly limit sample throughput.
As written, the EPA 537 requires a 27-minute cycle per
sample, but the method does allow flexibility in the column
used as long as there is sufficient resolution for the MS dwell
time for all compounds in a specific retention time window.
In the first chromatogram below, all target perfluorinated
alkyl acids were analyzed on a Raptor™ C18 column in under
8 minutes with a total cycle time of 10 minutes—resulting
in an approximately three-fold faster analysis than the EPA
method. While this analysis is significantly faster, there is
no sacrifice in peak resolution or selectivity, meaning all
fluorochemicals are easily identified and they elute as highly
symmetrical peaks that can be accurately integrated and
quantified by MS/MS. If PFOA and PFOS are the only target
fluorochemicals, the analysis can be further optimized, which
results in a fast, <2-minute separation with a total cycle time
of just 4.5 minutes, as shown in the second chromatogram.
Whether labs conducting perfluorinated alkyl acid analysis
by LC use longer target analyte lists or focus just on PFOA and
PFOS, the excellent peak shapes and separations achieved
here result in consistent, accurate quantification with much
shorter analysis times. By switching to a Raptor™ C18 column,
labs can process more samples per hour while still meeting
fluorochemical method requirements.