Motorbike frog (Litoria moorei) tissue untargeted metabolomics

Untargeted reversed-phase liquid chromatography high-resolution mass spectrometry profiling of four tissues (muscle, liver, fat and gonads/eggs) from wild-caught motorbike frogs (Litoria moorei) collected from 11 wetlands around Perth, Western Australia. The aim of collecting this data was to assess the metabolome in relation to accumulated metals and PFAS. We provide the raw data for future researchers to consider more detailed feature annotations.\nLineage: Materials\nThe study utilised OptimaTM LC-MS grade acetonitrile (ACN) and methanol (MeOH) from Thermo Fisher Scientific (Malaga, WA, Australia) with LC-MS grade formic acid obtained from Sigma Aldrich (North Ryde, NSW, Australia). A Milli-Q IQ 7000 water purification system (Merck Millipore) provided ultrapure LC-MS grade water. The stable isotope labelled internal standards (ISTD) phenylalanine-13C915N and tryptophan-d5 were obtained from Sigma Alrich (North Ryde, NSW, Australia), N-benzoyl-d5-glycine (hippuric acid-d5) was obtained from CDN Isotopes Inc. (PM Separations, QLD, Australia) and cholic acid-d4 was purchased from Cambride Isotope Laboratories Inc. (Novachem, VIC, Australia).\n\nSample preparation\n\nIf tissue samples were < 20 mg then the whole tissue was used, otherwise 20mg of liver, gonad/egg, muscle and fat tissue freeze-dried and homogenised with 20 µL methanol/acetonitrile 50/50 (v/v) using 2.8 mm stainless steel beads from Thermo Fischer Scientific (Malaga, WA, Australia) with a Precellys® 24 (Bertin Technologies, Singapore) tissue homogeniser for 2 × 20 seconds at 5,000 Hz. 150 µL tissue extract was vacuum dried using a France Etuves, XFP-020 (Chelles, France). Dried extracts were reconstituted in 75 µL water + 0.1 % formic acid containing internal standards at 4 µg/mL (phenylalanine-13C915N, tryptophan-d5), N-benzoyl-d5-glycin, cholic acid-d4). A pooled quality control (PQC) was generated by combining equal volumes of each study sample and analysed throughout the run to evaluate analytical stability.\n\nLiquid chromatography-mass spectrometry\n\nAnalysis was performed on a Waters Acquity I-class ultra-performance liquid chromatography systems (comprising a Binary Solvent Manager, thermostatic Column Manager and FL Sample Manager, Waters Corp., Milford, MA, USA) coupled to a Bruker Impact II quadrupole time-of-flight (Q-ToF) (Bruker Daltonics, Billerica, MA, USA) mass spectrometer.\n\nReversed-phase separation was performed on a Waters HSS T3 1.8 µm, 100 x 2.1 mm (Waters, Wilmslow, UK) kept at 40 °C. The mobile phase A consisted of water containing 0.1 % formic acid, and mobile phase B was acetonitrile containing 0.1 % formic acid. The flow rate was 0.4 mL/min. Initial conditions were 0 % B, increased via a linear gradient to 10 % B at 1.50 minutes, 60 % B at 7.50 minutes and on to 100 % B at 9.50 minutes, which was held until 11.50 minutes to wash the column. At 11.70 minutes, the composition was returned to initial conditions (0% B), allowing for re-equilibration until 14 minutes. The autosampler was maintained at 4 °C and 5 µL of sample was injected for analysis.\n\nElectrospray ionisation (ESI) was used in positive and negative mode. The Quadrupole Time-of-Flight Mass Spectrometry (QToF) instrument was operated to collect full scan MS data and MS/MS fragmentation spectra in the same analytical run using a data dependent modality offered by the Bruker autoMS/MS function modes over a mass range of m/z 20-1300. The capillary voltage was set at 4500V in positive ionisation mode and 3500 V in negative ionisation mode. Drying gas was set at 10 L a minute, gas temperature was 220 oC, and the nebuliser pressure was 2.2 bar. The end plate offset was set to 500 V. The collision energy for the MS scan was set to 6.0 eV and alternating low and high energy for MS/MS were set at 20 and 50 eV. MS1 scan rate was set at 12 Hz over the mass range of m/z 20-1300. Auto MS/MS was performed with 4 precursors automatically selected and data collected at a scan rate of 25 Hz per scan cycle, resulting in a total scan cycle time (MS1 + auto MS/MS) of 0.2 seconds. An internal mass calibration was performed by injection of 1 mM sodium formate solution in water:propan-2-ol (50:50, v/v) at the beginning of each run. Data were collected with Compass HyStar 5.1 and O-TOF Control version 5.2.