Agilent 7820a gas chromatograph

The total lipids from the whole body homogenates, liver samples, fillet samples, and diet samples were extracted according to Folch et al. [42 ] with modifications as in Torno et al. [22 (link)]. Samples were neutralized using potassium hydroxide (0.1 M) followed by the addition of the Folch reagent and subsequent centrifugation for 10 min at 2000× g to isolate the fatty acid methyl esters (FAMEs). The organic phase was collected to perform a second extraction with potassium hydroxide and the Folch reagent. After subsequent centrifugation (5 min at 2000× g) and drying of samples under a N₂ flux, the re-dissolved FAME samples were injected into a 7820A Agilent gas chromatograph with flame ionization detector (GC-FID; Agilent Technologies, Santa Clara, CA, USA). A FAME-standard was used for the identification of the retention times of the individual FAMEs. The fatty acid composition was calculated as percentage of single FAME relative to total FAMEs. The internal standard 13:0 methyl ester was used to calculate FAs as % DM of diet.

Fatty acid composition was analysed in frozen liver samples by gas chromatography with a flame ionization detector as described previously.^{(33 (link))} Fatty acid methyl esters (FAMEs) were synthesized by incubation with 0.5 M sodium methoxide, and the fatty acid composition was calculated as a percentage of the total identified FAMEs. Analysis of FAMEs was conducted in a 7820A Agilent gas chromatograph (Agilent Technologies Spain) equipped with an Agilent HP-23 capillary column (60 m × 250 µm × 0.25 µm, Agilent Technologies Spain) and helium (1.0 ml/min) as the carrier gas. The temperature protocol was as follows: initial temperature 100°C, ramp 8°C/min to 145°C (20 min), ramp 5°C/min to 195°C (5 min), ramp 5°C to 215°C (15 min), ramp 5°C to 230°C (5 min). Chromatograms were recorded and analysed using Agilent EZChrom Elite software (Agilent Technologies Spain). The method was validated with original standards for every fatty acid quantified. Additionally, tridecanoic acid (C13:0) was used as an internal standard, and in every case, a response factor of 1 was used.

The evaluation of ethylene adsorption performance was conducted in a 10 mm fixed-bed reactor, as illustrated in Figure S1. In this setup, a mixture of 500 mg of Ag/NZ5(X) and 500 mg of silicon dioxide (used as physical supports) were packed in the reactor. The composition of the ethylene standard gas comprised 100 ppm of ethylene, 21 wt.% oxygen, and approximately 79 wt.% nitrogen.
Breakthrough curves were used to evaluate the ethylene adsorption capacity and the reusability of Ag/NZ5(X). For measuring the breakthrough curves, an Agilent 7820A gas chromatograph (GC) was used to determine the ethylene concentrations of the gas stream. The flow rate of the gas stream was kept at 85 mL·min⁻¹ by using a mass flow controller (MFC) under the conditions of 25 °C and atmospheric pressure. Finally, the ethylene removal rate (R) and adsorption capacity (C) of Ag/NZ5(X) were calculated by using equations provided in the Supporting Information. The optimal performance among the samples is defined by the longest sustained near-complete ethylene removal (i.e., R > 99%) coupled with the highest adsorption capacity. This dual metric serves as the benchmark for determining the best ethylene adsorption performance in the study.