Elan 6000

ATR-FTIR spectra were recorded at a resolution of 4 cm⁻¹ over the 4000–700 cm⁻¹ range using a NICOLET IZ10 spectrometer (Thermo Scientific, Waltham, MA, USA) equipped with a germanium ATR crystal and a single reflection angle 45° horizontal ATR accessory. The UV-Vis spectroscopic analysis was performed using a DR 3900 UV-Vis spectrophotometer (Hach Lange, Loveland, CO, USA) equipped with 1 cm quartz cuvettes. High-resolution transmission electron microscopy (HR-TEM) analysis was carried out using transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) system (Titan 80-300, FEI, city, state abbrev if USA, country) with a super twin-lens operated at 300 kV and equipped with an annular dark field detector. The presence of various elements in the obtained nanoparticles was analysed using energy-dispersive X-ray spectroscopy (EDX, Aztec, Oxford Instruments, Abingdon, UK). ICP-MS (Elan 6000, Perkin Elmer, Waltham, MA, USA) was used to determine the Pd/Pt concentration.

Blood samples were collected from the jugular vein of weaned beef calves, at baseline and after 2, 4, 6 and 8 weeks of alfalfa hay consumption, into evacuated EDTA tubes (2 mL; final EDTA concentration 2 g/L; Becton Dickinson, Franklin Lakes, NJ) and stored on ice until they were frozen at -20°C to measure whole blood Se (WB-Se) concentrations. Selenium concentrations were determined by a commercial laboratory (Utah Veterinary Diagnostic Laboratory, Logan, UT) using an inductively coupled argon plasma emission spectrometry method. Selenium was measured using an ICP-MS (ELAN 6000, Perkin Elmer, Shelton, CT) method as previously described [3 (link)].

Whole-blood samples were collected within 12 to 48 h of birth (day 0), at 14 days of age, at 60 days of age, and again at weaning, into evacuated 2-mL EDTA tubes (final EDTA concentration of 2 g/L; Becton, Dickinson and Company, Franklin Lakes, NJ, USA) and stored on ice until they were frozen at −20 °C. Frozen whole-blood samples were shipped on dry ice to Utah Veterinary Diagnostic Laboratory, a commercial laboratory in Logan, UT, to measure concentrations of WB-Se. In short, 750 µL of whole blood was mixed with 750 µL of trace-metal-grade nitric acid in a 10-mL digestion tube. Next, the blood was digested for 2 h at 90 °C in the cap-sealed tube. After cooling down, the contents were transferred to another trace-metal-free tube. Next, 1 mL of the digested blood was transferred into another trace-metal-free tube, which already contained 9.0 mL of ultrapure water, to form a 5% nitric acid matrix. After vortexing, the sample was analyzed on an inductively coupled argon plasma emission spectrometer (ICP-MS; ELAN 6000, Perkin Elmer, Shelton, CT, USA) using a 4-point standard curve. A pooled QC sample dissolved in a 5% nitric acid matrix was analyzed after every 5 samples. If the pooled QC sample fell within ±5% of the reference value, the WB-Se analysis was considered acceptable.