Agilent 700 series icp optical emission spectrometers

Two-dimensional GO and GO–Ag NP images were obtained using TEM (JEM 2000EXII, JEOL, Tokyo, Japan). Sample structures were analyzed using X-ray diffraction (XRD, Siemens D5005, Oslo, Norway) to determine the element structure and phase purity. The 2θ diffractogram was scanned in the range of 5–80° at a scan rate of 4° min⁻¹ with Cu-Kα radiation. FTIR (Horiba FT-730G, Kyoto, Japan) was used to identify the functional groups of the sample in the range of 500–4000 cm⁻¹. A UV-visible spectrophotometer (V-650, Tokyo, Japan) was used to measure the change in the lateral size of GO and GO–Ag NP with various absorption wavelengths. The zeta potential and size distribution of GO and GO–Ag NPs were recorded in triplicate via a light scattering instrument (Zetasizer, 2000 HAS, Malvern, Worcestershire, UK). The Ag content was analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES, Agilent 700 Series ICP Optical Emission Spectrometers, Victoria, Australia).

The concentrations of yolk minerals, including Ca, Fe, K, Mg, Mn, Na, P, Sr and Zn, were measured at each incubation time using an optical spectroscope. The samples were homogenized, weighed (as-is and dry weight) and freeze dried, and then, the concentrations of Ca, Cu, Fe, Mg, Mn, Na, K, Sr and Zn were measured. After powdering the dry samples, 0.5 g of each sample was placed in a 50 mL tube, and 5 mL of nitric acid was added. The samples were covered with a watch glass and heated in an oven at 50 °C for 2 h; then, the temperature was increased to 90 °C for 30 min. After cooling to room temperature, 2 mL of hydrogen peroxide was added. The samples were then heated again for 10 min at 90 °C; then, the temperature was raised to 120 °C for 30 min, and finally, the samples were diluted with 30 mL of distiller water. The prepared yolk samples were analyzed for mineral concentration using inductively coupled plasma optical emission spectroscopy (iCAP) according to manufacturer’s instructions (Agilent 700 Series ICP Optical Emission Spectrometers) [13 (link)]. From this, measured concentrations of these minerals were obtained. The yolk mineral concentrations were multiplied by the dried yolk weight to determine the absolute amount of mineral in each yolk. The dry yolk weight was subtracted from the fresh yolk weight to give the approximate water content.