Lc ms grade methanol

The IS and substrate of each MPS were obtained from PerkinElmer (Waltham, MA, USA; Figure 3 and Table 3). Substrate concentrations were determined as described previously [30 (link)]. LC-MS grade methanol, acetonitrile, and ultrapure water were purchased from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). DBS samples for quality control were provided by PerkinElmer. The reaction buffer was prepared by dissolving each substrate and IS corresponding to each type of MPS in 5 mM cerium acetate, 50 mM sodium acetate, and 0.042 mM D-saccharic acid 1-4-lactone at pH 5.0. The reaction buffer was stored at 4 °C and used within 2 weeks of preparation.

Fish oil DHA-46 and GNO were provided by Tama Biochemical Co., Ltd. (Tokyo, Japan) and NPO Arcoiris Naturaleza (Matsudo, Chiba, Japan), respectively. Corn oil was purchased from Oriental Yeast Co., Ltd. (Tokyo, Japan). LC/MS grade methanol, 2-propanol, and ultrapure water were purchased from Wako Pure Chemical Industries (Osaka, Japan). OA, lysophosphatidylcholine (18:1), phosphatidylcholine (18:1/18:1), DHA, phosphatidylcholine (22:6/22:6), and sodium formate were purchased from Sigma-Aldrich (St. Louis, MO, USA). AA was purchased from Cayman Chemical (Ann Arbor, Michigan, MI, USA).

Human-, mouse-, and rat-sera were purchased from Sigma-Aldrich Co. (St. Louis, MO, USA), authentic standard compounds from Sigma-Aldrich and Avanti Polar Lipids, Inc. (Alabaster, AL, USA), and ammonium acetate from Sigma-Aldrich. LC/MS grade distilled water and LC/MS grade methanol were purchased from Wako Pure Chemical Industries Ltd. (Osaka, Japan).

Technical mixture standards of SCCPs (55.5 and 63% Cl) and MCCPs (42 and 57% Cl) were purchased from Dr Ehrenstorfer GmbH (Augsburg, Germany). Analytical standards of plasticizers di-2-ethylhexyl-terephthalate (DEHT), 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), phthalic acid esters di-n-butyl phthalate (DNBP), bis-2-ethylhexyl phthalate (DEHP) and di-(2-propyl heptyl) phthalate (DPHP) were purchased from AccuStandard (New Heaven, CT, USA). LC/MS grade methanol, Japan Industrial Standard grade ammonium acetate and dioxin-analysis-grade toluene, n-hexane, acetone and silica gel impregnated with 55% w/w sulphuric acid were obtained from Fujifilm Wako Pure Chemical Corporation (Osaka, Japan). Dioxin-analysis-grade dichloromethane was purchased from Kanto Chemical Co. Inc. (Tokyo, Japan) and Milli-Q water was supplied by a Synergy UV ultrapure purification system (Millipore Corporation, Billerica, MA, USA). Pesticide grade iso-octane was purchased from VWR (Leuven, Belgium).

Isovaleryl-l-carnitine and 2-methylbutyryl-l-carnitine were purchased from Merck (Darmstadt, Germany). l-Pivaloylcarnitine was purchased from AptoChem (Montreal, QC, Canada). Valeryl-l-carnitine was purchased from Cambridge Isotope Laboratories, Inc. (Tewksbury, MA, USA). LC–MS-grade methanol, ultrapure water, ammonium formate, formic acid, and acetonitrile were purchased from FUJIFILM Wako Pure Chemical Corporation (Osaka, Japan). The mobile phase for FIA-TMS was provided using a NeoBase Kit (Perkin Elmer, Waltham, MA, USA).

Metabolomics analysis was performed at Human Metabolome Technologies (Yamagata, Japan)64 (link). In brief, PLC/PRF/5 cells were washed with 5% mannitol solution and permeated by LC/MS grade methanol (Wako) containing Internal Standard Solution 1 (HMT) at room temperature. After ultrafiltration of the extracts, metabolomics analysis was performed by CE-TOF/MS, followed by normalization of the signals to the cell number.