Agilent 7800 icp ms

The effect of pH on Sb(v) sorption on the materials was examined over the pH range from 1 to 11. Batch samples were prepared using 2 g L⁻¹ adsorbent concentration, and 10 mg L⁻¹ (0.082 mmol L⁻¹) Sb(v) in 0.01 M NaNO₃ solution. The pH of the solution was adjusted with a small amount of either NaOH or HCl. The samples were equilibrated for 24 h before phase separation that was carried out by centrifugation at 2100g for 10 min followed by syringe filtration (Acrodisc LC 0.2 μm PVDF). Equilibrium pH values were determined after the phase separation. Sample aliquots were taken and diluted with an acid mixture of HCl and HNO₃ for Sb concentration measurement with an Agilent 7800 ICP-MS.

0.5 mL Caco-2 cells were seeded into the upper chamber in 12-well transwell dishes (Corning Costar Co., Cambridge, MA) at a density of 2 × 10⁵ cells per mL in serum-containing DMEM and 1.5 mL serum-containing DMEM was added to the lower chamber. Each medium was changed the other day, and every day after seven days. The monolayers' transepithelial electric resistance (TEER) was determined using the Millicell ERS-2 system (Millipore Corp., New Bedford, MA, USA). Experiments on zinc uptake were conducted when the cells had TEER values over 1000 Ω cm².
The assay was performed after Caco-2 cells were incubated for one hour with DMEM containing 2% FBS. The cells were then washed three times with Dulbecco's–Hanks balanced salt solution (D–Hank's). Then, add 0.5 mL samples (the final concentration of ZnSO₄ is 40 μM, and the final concentration of α-La, β-LG, and BSA is 1%) to the upper chamber and 1 mL D–Hank's to the lower chamber. Each group was set up with three replicates. After 2 h incubation in the incubator, the lower chamber samples were collected and cleaned once with 0.5 mL D–Hank's and combined. The zinc content was detected by inductively coupled plasma mass spectrometry (ICP-MS, Agilent 7800 ICP-MS, USA).

Shoots were harvested, dried at 60°C for 48 h, and digested with HNO₃ and H₂O₂ at 100°C. Digested samples were dissolved and diluted with 0.08 M HNO₃ and analyzed using inductively coupled plasma-mass spectrometry (Agilent 7800 ICP-MS; Agilent Technologies, Santa Clara, California, USA). All experiments were conducted with three independent biological replicates.

The target elements were eight essential trace metal elements (chromium [Cr], manganese [Mn], iron [Fe], cobalt [Co], copper [Cu], zinc [Zn], selenium [Se], and molybdenum [Mo]) in medium and lysate, and Mn and Zn in urine and serum.
All elements were measured by inductively coupled plasma mass spectrometry (ICP-MS; Agilent 7800 ICP-MS, Agilent Technologies, California, USA). The reagents used were nitric acid 1.38 (Kanto Chemical, Tokyo, Japan) and ICP-MS mixing standard XSTC-622 (SPEX CertiPrep, New Jersey, USA). Medium, lysate and urine were diluted 10-fold and serum was diluted 20-fold before analysis. (1 + 99) nitric acid was used as the diluent. For urine and serum, if they exceeded the calibration range, both were diluted 100-fold with (1 + 99) nitric acid. Equal amounts of yttrium standard solution (Kanto Chemical, Tokyo, Japan) were added to each test solution as an internal standard.
Since urinary concentrations of elements are affected by water intake, the amount of the element excreted in 24 h was evaluated. Urine specific gravity was determined using a digital urine specific gravity refractometer (UR-S, ATAGO, Tokyo, Japan), and 24-h excretion was calculated based on total urine volume and urine specific gravity. The 24-h excretion was normalized by body weight.