Full-scan accurate mass selectivity of ultra-performance liquid chromatography combined with time-of-flight and orbitrap mass spectrometry in hormone and veterinary drug residue analysis

Abstract

The applicability of ultra-performance liquid chromatography (UPLC) combined with fullscan accurate mass time-of-flight (TOF) and Orbitrap mass spectrometry (MS) to the analysis of hormone and veterinary drug residues was evaluated. Extracts from blank bovine hair were fortified with 14 steroid esters. UPLC-Orbitrap MS performed at a resolving power of 60,000 (FWHM) enabled the detection and accurate mass measurement (Ͻ3 ppm error) of all 14 steroid esters at low ng/g concentration level, despite the complex matrix background. A 5 ppm mass tolerance window proved to be essential to generate highly selective reconstructed ion chromatograms (RICs) having reduced background from the hair matrix. UPLC-Orbitrap MS at a lower resolving power of 7500 and UPLC-TOFMS at mass resolving power 10,000 failed both to detect all of the steroid esters in hair extracts owing to the inability to mass resolve analyte ions from co-eluting isobaric matrix compounds. In a second application, animal feed extracts were fortified with coccidiostats drugs at levels ranging from 240 to 1900 ng/g. UPLC-Orbitrap MS conducted at a resolving power of 7500 and 60,000 and UPLC-TOFMS detected all of the analytes at the lowest investigated level. Thanks to the higher analyte-to-matrix background ratio, the utilization of very narrow mass tolerance windows in the RIC was not required. This study demonstrates that even when the targeted sample preparation from conventional LC-MS/MS is applied to UPLC with full-scan accurate mass MS, false compliant (false negative) results can be obtained when the mass resolving power of the MS is insufficient to separate analyte ions from isobaric co-eluting sample matrix ions. The current trend towards more generic and less selective sample preparation is expected to aggravate this issue further. (J Am Soc Mass Spectrom 2009, 20, 451-463)

Confirmation of Pinnatoxins and Spirolides in Shellfish and Passive Samplers from Catalonia (Spain) by Liquid Chromatography Coupled with Triple Quadrupole and High-Resolution Hybrid Tandem Mass Spectrometry

“…On the other hand, physical resolution and precision in mass accuracy measurements of the instrument determine the width of the mass error tolerance: setting a too narrow tolerance may lead to false negatives due to shifts in accurate mass measurements caused by hidden isobaric interferences and/or distortion of chromatographic peaks [50,51]. Defining an appropriate mass error tolerance seems to be a fit-for-purpose task [50], thus taking into account the resolution of our LTQ Orbitrap Discovery ® (resolution 30,000 at 400 m/z FWHM) and the good precision in mass accuracy measurements for PnTX-G and SPX-1 (<2 ppm, Section 2.4.2), we screened the samples for PnTXs and SPXs with a 10 ppm mass tolerance window.…”

Challenges in the Measurement of Antibiotics and in Evaluating Their Impacts in Agroecosystems: A Critical Review

“…Although high-resolution MS instruments are more expensive than QqQ MS, they are becoming more widely available in many environmental laboratories because of the increased interest in nontarget analysis, where unknown contaminants are detected and identified based on the elemental composition predicted by accurate mass measurements and mass spectral fragmentation pattern. Screening methods for antibiotics have been performed by Q-ToF MS in waste and surface waters (Ibanez et al, 2009) and in animal hair and feed (van der Heeft et al, 2009).…”

Comparison of Tandem Quadrupole Mass Spectrometry and Orbitrap High Resolution Mass Spectrometry for Analysis of Pharmaceutical Residues in Biota Samples

“…Antibiotics have received a special attention among pharmaceuticals for their increased application in human therapy, aquaculture and livestock agriculture [2], [3]. The maximum acceptable residue levels (MRLs) for antibiotics in foodstuff are determined in the European Union by the Commission Regulation No.…”