Methanol hipersolv chromanorm lc ms grade

Water (18.2 MΩ cm) provided from a Milli-Q Academic water purification system (Millipore GmbH, Vienna, Austria) was used throughout this work. Nitric acid (65% p.a., further purified by subboiling), pyridine (≥ 99%), trifluoroacetic acid (≥ 99.9%), ammonia solution (≥ 25% p.a.), hydrogen peroxide (30% p.a.) and formic acid (≥ 98% p.a.) were purchased from Carl Roth GmbH & Co (Karlsruhe.
Germany). Malonic acid (N 99%) was obtained from Sigma Aldrich (Vienna, Austria). Methanol HiPerSolv Chromanorm (LC-MS grade) was purchased from VWR International (Vienna, Austria). For the determination of the total As content by ICPMS, a 1000 mg As L -1 single element standard purchased from CPI International (Santa Rosa, CA, USA) was used. For speciation analysis, standards of arsenic species were prepared from stock solutions containing 1000 mg As L -1 of each of the following compounds: arsenobetaine, trimethylarsine oxide, arsenocholine, tetramethylarsonium iodide, and arsenosugar-glycerol (purity of compounds N99% by NMR and HPLC/mass spectrometry, previously synthesized in house), dimethylarsinate prepared from sodium dimethylarsinate (Fluka, Buchs, Switzerland), and arsenate prepared from Na 2 HAsO 4 7H 2 O (Merck, Darmstadt, Germany). A characterized extract of Fucus serratus was used as a source of the anionic arsenosugars (Madsen et al., 2000) (link).