Steps to reproduce
The aerosol samples were collected from Chichijima Island (27.06° N and 142.21° E) located at the Ogasawara Downrange Station of the Japan Aerospace Exploration Agency (JAXA). A high-volume air sampler (Kimoto AS-810A) was used to collect the Total Suspended Particulate (TSP) samples. The TSP samples were collected on pre-combusted (450°C for 6 h) quartz fiber filters at a flow rate of 1.0 m3 min−1 on a weekly basis from January 2010 to December 2012. The sample filters were extracted with a dichloromethane and methanol mixture (2:1) under ultrasonication. The extracts were then derivatized with N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% TMS chloride in the presence of 10 µL of pyridine in a 1.5 ml to convert the hydroxy groups into corresponding trimethylsilyl (TMS) ethers and the carboxyl groups into TMS esters. GC-MS analyses of samples were performed on an Agilent model 7890 GC coupled to an Agilent model 5975 mass selective detector (MSD). The mass spectrometer was operated in the electron ionization (EI) mode at 70 eV and scanned in the m/z range 40–650 Da. GC-MS data were acquired and processed with an Agilent GC/MSD ChemStation software.