Icp oes agilent 5110 svdv

The samples collected after 180 min of hydrolysis were thawed at 4 °C before their dilution 1/20 in Milli-Q water. Potassium, sodium and sulfur concentrations were determined by optical emission spectrometry with inductively coupled plasma as atomization and excitation source (ICP-OES Agilent 5110 SVDV Agilent Technologies, Victoria, Australia), using the following wavelengths (in nm): 766.491 (K), 588.995; 589.592 (Na), 181.972; 180.669 (S). The analyses for all ions were carried out in axial and/or radial view. For chlorides, the samples were analyzed with Flow Injection Analysis (FIA) (Quikchem 8500 series 2, Zellweger Analytic, inc., Lachat Instruments Division, Milwaukee, WI, USA) with Quikchem method 10-117-07-1-C: Determination of chloride by Flow Injection Analysis colorimetry.

As described by Dufton et al. [27 (link)], the samples collected during ED treatment were thawed at 4 °C before their dilution 1:20 in Milli- Q water to reach a final volume of 10 mL. Calcium, potassium, magnesium, sodium, and phosphorus concentrations were determined by optical emission spectrometry with inductively coupled plasma as an atomization and excitation source (ICP-OES Agilent 5110 SVDV Agilent Technologies, Victoria, Australia), using the following wavelengths (nm): 393.366; 396.847; 422.673 (Ca), 766.491 (K), 279.553; 280.270; 285.213 (Mg), 588.995; 589.592 (Na), 177.434; 178.222; 213.618; 214.914 (P). The analyses for all ions were carried out in axial and/or radial view. The demineralization rate based on the mineral concentration for each treatment was calculated using Equation (1) while considering the total ion concentration in acid whey at the beginning (C_i in ppm) and at the end (C_f in ppm) of each treatment.

The ash content of the membranes was determined according to the AOAC method 945.46 [30 ]. First, membrane coupons of 4 cm² were weighted into pre-weighted crucibles and placed in a furnace (Lindberg/Blue M Moldatherm Box Furnaces, Thermo Fisher Scientific, Waltham, MA, USA) at 550 °C for 24 h and weighed [31 (link)]. The analysis was performed in triplicate, and the ash content was calculated using Equation (3): $$\mathrm{Ash}\mathrm{content}=\left(\frac{\mathrm{Sample}\mathrm{mass}\mathrm{after}\mathrm{incineration}}{\mathrm{Sample}\mathrm{mass}\mathrm{before}\mathrm{incineration}}\right)\times 100$$
To determine the mineral content, the method described by Dufton et al. (2018) was used [4 (link)]. Ash samples were solubilized in 2 mL of 25% nitric acid and 8 mL of miliQ water. The solutions were filtered with a 0.45 µm PTFE filter (CHROMESPEC Syring Filter, Chromatographic Specialties, Brockville, ON, Canada). Calcium, magnesium, potassium, sodium, and phosphorus were determined using an Agilent 5110 SVDV ICP-OES (Agilent Technologies, VC, Australia), using the following wavelengths: 393.366, 396.847, 422.673 (Ca); 766.491 (K); 279.553, 280.270, 285.213 (Mg); 588.995, 589.592 (Na); 177.434, 178.222, 213.618, 214.914 (P). The analyses for all the ions were carried out in radial and/or axial view. The analysis was carried out in triplicate, and the results were expressed in g/100 g of membrane on a dry basis. The limit of detection was parts per billion (ppb) [32 (link)].