Abstract
A method based on QuEChERS extraction and LC-quadrupole-Orbitrap™ MS detection was established utilising an
improved fully non-targeted way of data acquisition with and without fragmentation. A full-scan acquisition event
without fragmentation (resolving power 70 000) was followed by five consecutive fragmentation events (variable data
independent acquisition – vDIA; resolving power 35 000) where all ions from the full-scan range are fragmented.
Compared with fragmentation in a single event (all-ion fragmentation – AIF), this improves both selectivity and
sensitivity for the fragment ions, which is beneficial for screening performance and identification capability. The
method was validated, using the data from the same measurements, for two types of analysis: quantitation/identification
and qualitative screening. The quantitative validation, performed according to the guidelines in SANCO/12571/
2013, tested the performance of the method for 184 compounds in lettuce and orange at two spiking levels: 10 and
50 ng g−1. The validation showed that the vast majority of the compounds met the criteria for trueness and precision
set in the SANCO guidance document. In the qualitative validation the same 184 compounds were used to test the
untargeted screening capabilities of the method. In this validation the compounds were spiked at three levels into 11
different fruit and vegetable matrices, which were measured twice on separate days. Taking all data from the
qualitative validation together, an overall detection rate of 92% was achieved at the 10 ng g−1 level, increasing to
98% at 200 ng g−1. A screening detection limit (as defined in the SANCO guidelines) of 10 ng g−1 could be achieved
for 134 compounds. For 39 and two pesticides the SDL was 50 and 200 ng g−1, respectively. For the other nine
compounds no SDL could be established. The identification (ion ratio) criteria as recommended in the SANCO
document could be met for 93% of the detected pesticide/matrix/concentration combinations. The outcome of both
validations shows that the described method can be used to combine quantitative analysis and the identification of
frequently detected pesticides (so far typically done using triple quadrupole MS/MS) with a qualitative screening to be
used for a wide range of less frequent detected compounds in one measurement
improved fully non-targeted way of data acquisition with and without fragmentation. A full-scan acquisition event
without fragmentation (resolving power 70 000) was followed by five consecutive fragmentation events (variable data
independent acquisition – vDIA; resolving power 35 000) where all ions from the full-scan range are fragmented.
Compared with fragmentation in a single event (all-ion fragmentation – AIF), this improves both selectivity and
sensitivity for the fragment ions, which is beneficial for screening performance and identification capability. The
method was validated, using the data from the same measurements, for two types of analysis: quantitation/identification
and qualitative screening. The quantitative validation, performed according to the guidelines in SANCO/12571/
2013, tested the performance of the method for 184 compounds in lettuce and orange at two spiking levels: 10 and
50 ng g−1. The validation showed that the vast majority of the compounds met the criteria for trueness and precision
set in the SANCO guidance document. In the qualitative validation the same 184 compounds were used to test the
untargeted screening capabilities of the method. In this validation the compounds were spiked at three levels into 11
different fruit and vegetable matrices, which were measured twice on separate days. Taking all data from the
qualitative validation together, an overall detection rate of 92% was achieved at the 10 ng g−1 level, increasing to
98% at 200 ng g−1. A screening detection limit (as defined in the SANCO guidelines) of 10 ng g−1 could be achieved
for 134 compounds. For 39 and two pesticides the SDL was 50 and 200 ng g−1, respectively. For the other nine
compounds no SDL could be established. The identification (ion ratio) criteria as recommended in the SANCO
document could be met for 93% of the detected pesticide/matrix/concentration combinations. The outcome of both
validations shows that the described method can be used to combine quantitative analysis and the identification of
frequently detected pesticides (so far typically done using triple quadrupole MS/MS) with a qualitative screening to be
used for a wide range of less frequent detected compounds in one measurement
Original language | English |
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Pages (from-to) | 1628-1636 |
Journal | Food Additives & Contaminants. Pt. A, Chemistry, Analysis, Control, Exposure & Risk Assessment |
Volume | 32 |
Issue number | 10 |
DOIs | |
Publication status | Published - 2015 |
Keywords
- fruits
- LC-MS
- method validation
- pesticides
- vegetables