Agilent 1260 infinity quaternary pump vl

The mycelia were collected from 10 mL culture samples of three randomly selected shake flasks, vacuum-filtered, washed with demineralized water, dried in a heat oven for 120 min at 100 °C and immediately weighed. The culture filtrates of each shake flask were collected for extracellular ABA quantification. ABA content was determined with a plant hormone abscisic acid ELISA kit (CUSABIO, Cat # CSB-E09159PI) following the manufacturer’s instructions. The ABA content was also confirmed by HPLC with the Agilent 1200 Pure Liquid Chromatography system (an Agilent 1260 Infinity Quaternary Pump VL with an Agilent 1260 Infinity Standard Autosampler and an Agilent 1260 Infinity Variable Wavelength Detector) and a Luna^® 5 μm C18(2) LC Column (Phenomenex, Cat # 00G-4252-E0). ABA was quantified by the absorption at 254 nm using a standard curve generated using a commercial S-(+)-ABA (98% w/w, Lomon Bio Technology Co., Ltd., Sichuan, China). The quantity of ABA was calculated from the ratio between the integrals of the standard sample and that of the corresponding curve of the experimental samples. All these measurements were performed independently in triplicate, and the values are shown as the means ± standard error in the figures.

For the separation of individual arsenic species, we used an Agilent Technologies 7700 series ICP-MS instrument (Agilent Technologies, Santa Clara, CA, USA), equipped with a lowflow sample introduction system and patented high matrix introduction kit. The HPLC system (Agilent Technologies) consisted of an Agilent 1260 Infinity Quaternary Pump VL, standard auto-sampler, and thermostat column compartment, equipped with Peltier cooling and heating apparatus for providing temperature stability and application flexibility. All samples were filtered with a 0.22 μm membrane before being placed into chromatographic vials (Agilent Technologies), then placed on the auto-sampler tray. A PRP X-100 anion-exchange HPLC column (5 μm, 4.6 mm×250 mm, Hamilton, Bonaduz, Switzerland) was used for arsenic species separation. The column was packed with a 55% cross-linked polystyrene divinylbenzene copolymer functionalized with quaternary ammonium anion-exchanger groups. The outlet of the column was directly connected to the sample introduction system of ICP-MS instrument. Reading data were collected by using Mass Hunter Workstation version B.01.01 (Agilent Technologies). The operating conditions for HPLC and ICP-MS are shown in Table 1.