710 es icp spectrophotometer

The chemical composition and functional
groups were analyzed using Fourier transform infrared spectroscopy
(FTIR-Varian 670-IR spectrometer). The morphology and the electron
diffraction images of the sorbent were obtained from transmission
electron microscopy (HR-TEM JEOL2100PLUS with STEM/EDS capability
at 120 and 200 kV, respectively). Chemical oxidation states of each
element were obtained by X-ray photon spectroscopy (XPS-Escalab Xi+-Thermo
Scientific). Elemental compositions for Fe, C, and O were also obtained
from XPS elemental survey analysis. Detection of lithium ions and
other alkali and alkaline cations in brine solutions before and after
being soaked with sorbents was analyzed using a simultaneous inductively
coupled plasma optical emission spectrometer (Varian 710-ES ICP Spectrophotometer).

Eluents
were analyzed for lithium ions using a simultaneous inductively coupled
plasma optical emission spectrometer (ICP-OES) with trace element
analysis capability for wavelengths from 177 to 785 nm (Varian 710-ES
ICP Spectrophotometer) in 3% (v/v) nitric acid solution. All measurements
were taken in three replicates. In a typical sample preparation method
for ICP analysis, the eluents were filtered through a 0.45 μm
filter. Next, the filtered eluents were diluted to less than 100 mg/L
concentration by adding 3% (v/v) nitric acid solution. For preparation
of standards, the lithium standard (1.0 mL) was added to 3% (v/v)
nitric acid solution (9.0 mL) to make a lithium stock standard with
a concentration of 100 ppm. Using serial dilutions, other lower concentrations
of the standards were prepared in 3% (v/v) nitric acid solution.