1200 infinity

The concentration of total weak acid was determined by conductometric titration. At first, 50 mL of the rooting solution was repeatedly passed through 50 g of acid-free cation exchange resin (CER) (AMBERLITE IR-120 H⁺) until the eluate attained a constant pH. The titration was carried out on a known volume of the final eluate with 0.05 N ammonium hydroxide (NH₄OH) as the titrant. The pre-standardized NH₄OH was added in a small increment, preferably 0.1 mL. The electrical conductivity of the titrant was measured after each incremental addition, and titration was continued until the EC attained a constant value. The concentration of the total weak acid was calculated using the following formula:
where v = volume of the NH₄OH consumed to neutralize weak acid (mL), N = normality of the NH₄OH solution, and V = volume of the rooting solution taken (20 mL).
Mainly, malic, succinic, citric, and lactic acids have been reported as important components in the root-exudate of rice [29 (link)]. In the present investigation, these acids were quantified by high-performance liquid chromatography (1200 Infinity; Agilent Technologies, Santa Clara, CA, USA) following the procedure of Krishnapriya and Pandey (2016) [30 (link)].

The TAG compositions of two Impatiens seed oils were performed by the incremental approach [21 , 22 (link)] based on the retention parameters, and the compositions of TAG were confirmed using the information on both their molecular ions of MS and electronic absorption spectra. The capacity factors (k) were deduced using column void time (t_o), calculated by the homologous series method [23 (link)]. In the present work, the retention time of series Pr₃ - Pr₂Ln - PrLn₂ - Ln₃ was used, and void time (t_o) was calculated to be 2.625 min and 2.358 min for Shimadzu LC20 chromatographic and Agilent 1200 Infinity chromatography systems, respectively in current conditions.
Mole fraction of TAGs on the chromatogram was performed by the formula:
Mole fraction of fatty acid was calculated using mole fractions of all TAGs, taking into account the numbers of the acid substituents (n_ij), in each TAGs:

Total RNA was extracted from E. histolytica trophozoites that were incubated with E. coli K12/∆QueC (a kind gift of Prof. Valérie de Crécy-Lagard, University of Florida, Gainesville, FL, USA) using the Monarch Total RNA Miniprep Kit (NEW ENGLAND BioLabs, Ornat, Nes Ziona, Israel). According to the manufacturer’s instructions, the absence of mechanical disruption during the cell lysis step favors the extraction of E. histolytica RNA over E. coli RNA using the detergent-based lysis buffer. tRNA samples were purified by high-performance liquid chromatography (1200 Infinity, Agilent, Santa Clara, CA, USA) using a size exclusion column (300 × 7.8 mm, 300 Å, Agilent, Santa Clara, CA, USA) with an isocratic mobile phase (100 mM ammonium acetate, pH 7.6, 40 °C) at a flow rate of 1 mL/min. tRNA fractions were collected and further dried by SpeedVac vacuum concentrators. These tRNA samples were reconstituted in RNase-free water, measured on a Nanodrop spectrophotometer 2000 (Thermo Fisher Scientific, Waltham, MA, USA) and quality checked on a bioanalyzer nano chip (Agilent, Santa Clara, CA, USA).

An Agilent 1200 Infinity (Waldbronn, Germany), equipped with a diode array detector and a Kinetex C18 reverse phase LC column Kinetex C18 (100 × 4.6 mm; particle size 2.6 μm; pore size 10 nm, Phenomenex), were used for analyses. The mobile phase consisted of acetonitrile and a 15 mM potassium dihydrogen phosphate solution (pH = 4.7), ran in an isocratic elution in 55:45 (v/v) ratio, at a flow rate of 1.5 mL per minute. The column temperature was maintained at 313 K. The injection volume was equal to 20 μL. The total run time was 3 min. The retention time of POS was 1.8 min. POS detection was carried out at λ = 262 nm. Linearity was confirmed within the concentration range of 7.8–54.4 μg/mL (R² = 0.9997). Each measurement was performed in triplicate (n = 3). Average values and standard deviations (SDs) were calculated.

The biomass‐specific fucoxanthin content (ω_FX) was analyzed with an HPLC (1200 Infinity; Agilent), according to the method by Gille et al. (2015 (link)) as previously described by (Derwenskus et al., 2019 (link)). Fucoxanthin was analyzed daily as biological triplicates.

The chromatographic profiling of Fr-BuVt was investigated via high performance liquid chromatography (HPLC) (Agilent 1200 Infinity) with quaternary pump and automatic injector (1200 Hip Als), coupled to mass spectrometry (3200 QTRAP® – Linear Ion Trap), AB SCiex. Chromatographic separations were performed using a Luna C-18 (250 × 4.6 mm, 5 μm; Phenomenex) column, conditioned in a column oven at 35 °C. The solvent system was MeOH (solvent A) and H₂O (solvent B) with 0.1% of formic acid. The gradient was 5–100% of A in B over 60 min.
The ionization via electrospray (Turbo Ion Spray) was performed in negative mode. Ionization source conditions: Ion Spray: − 4500 V, Curtain Gas: 20 psi; Temperature: 650 °C, Gas 1: 50 psi; Gas 2: 50 psi, Interface heater: ON, DP (Declustering Potential) -25.0 V, EP (Entrance Potential) -10.0 V and CEP (Cell entrance potential) -16.0 V. Ion scan mode (EMS – Enhanced Scan): 100–800 Da EPI (Enhanced product ion) Collision energy: 35.0 V +/− 15.0 V. The Fr-BuVT was dissolved in MeOH:H₂O (1:1, v/v), filtered in Polytetrafluoroethylene (PTFE) membrane (0.45 μm) and analysed at a final concentration of 1 ppm.