Ultrapure water purifier

Quercetin, quercitrin, isorhamnetin, tamarixetin, L-glutamine, and trypsin were purchased from Sigma (USA). HPLC-grade methanol was obtained from Thermo Fisher (Waltham, MA, USA), Dulbecco’s Modified Eagle’s medium (DMEM) from Gibco (Waltham, MA, USA), and fetal bovine serum and nonessential amino acids from Hyclone (Logan, UT, USA). Ultrapure water was prepared by using a MilliPore ultrapure water purifier (St. Louis, MO, USA). All other chemicals used in the experiments were of analytical grade. The 12-well Millicell plates were purchased from Millipore. LC/MS (Agilent 1100 LC/MS DVL, DE) was obtained from Agilent (Santa Clara, CA, USA).

The Brassica chinensis L. plants used in these experiments were from farmland in the Zhuanghang experimental base, Shanghai Academy of Agriculture Science. The neonicotinoids included water-dispersible granules of 70% IMI, water-soluble powder of 20% ACE, and water-dispersible granules of 25% TMX, which were from Bayer Crop Science (Hangzhou, China), Noposion (Shenzhen, China), and Guanlong Agrochemical (Hengshui, China), respectively. Standards samples of IMI (purity > 99.5%), ACE (purity > 99%), and TMX (purity > 99%) were obtained from Dr. Ehrenstorfer (Augsburg, Germany).
High-performance liquid chromatography (HPLC)-grade acetonitrile was from ANPEL (Shanghai, China), and analytical-grade sodium chloride was from Lingfeng (Shanghai, China). A 2-milliliter dispersive solid-phase extraction (dSPE) purifier tube containing 150 mg anhydrous magnesium sulfate, 25 mg primary secondary amine (PSA), and 7.5 mg graphitized carbon black (GCB) was obtained from ANPEL (Shanghai, China). Milli-Q quality water was made using an Ultra-pure Water Purifier (Millipore, Burlington, MA, USA) for experiments.