Agilent 5110 icp oes

Extract samples were thawed and 1.00 mL of each was digested with nitric acid (3 mL) in closed Teflon vessels with the use of a Mars 6 microwave sample digestion system (CEM, Matthews, NC, USA). The two-step digestion process was performed: ramping to temperature 180 °C for 20 min and holding at 180 °C for 30 min. Following the digestion, the solution was diluted to a final volume of 5.00 mL with MilliQ water. The concentration of macro elements (Ca, Mg, K, Na, and P) and trace elements (Co, Cr, Cu, Mn, Mo, Fe, and Zn) was determined using the inductively coupled plasma optical emission spectrometer (Agilent 5110 ICP-OES, Agilent, Lexington, MA, USA) with parameters, wavelengths, analytical standards, and reference materials employed as described previously [43 (link)]. Se concentration was determined using electrothermal atomic absorption spectrometry (ETAAS) with a Zeeman background correction. Analyses were performed using the SpectrAA 280Z (Agilent Technologies, Mulgrave, Australia) instrument with pyrolytic graphite tubes and an Se hollow cathode lamp (wavelength 196.0 nm, current 10 mA, slit 1.0 nm) [44 (link)]. As a chemical modifier, palladium solution (10 μL of 500 mg L⁻¹ for 20 μL of sample) was used. The limit of detection was 0.01 mg kg⁻¹ and the uncertainty of results were obtained at the 5% level.

The inductively coupled plasma optical emission spectrometer Agilent 5110 ICP-OES (Agilent, USA) was used in As, B, Ca, K, Mg, Na, P, S, and Si determination. A synchronous vertical dual view (SVDV) of the plasma was accomplished with dichroic spectral combiner (DSC) technology which allows the axial and radial view to be analyzed simultaneously. Common instrumental conditions were applied: radio frequency (RF) power 1.2 kW, nebulizer gas flow 0.7 L min⁻¹, auxiliary gas flow 1.0 L min⁻¹, plasma gas flow 12.0 L min⁻¹, charge coupled device (CCD) temperature − 40 °C, viewing height for radial plasma observation 8 mm, accusation time 5 s, 3 replicates. The content of S for selected samples was checked with a FLASH 2000 analyzer (Thermo Scientific) with FPD detector. Traceability was verified using the standard addition methods, and recoveries at the level of 80–120% were found as satisfactory. General characteristics of fundamental analytical data are present in supplementary data (Table S1).

The main parameters of the aqueous samples, i.e., MWW, CPW, and CO₂-bubbled effluent, were measured at the ISO/IEC 17025:2017
accredited laboratory (Magalies Water Services, Brits, North West,
South Africa). Specifically, the pH, temperature, and EC were measured
using an HQ40d Portable Meter (Hach Company). The DR6000 spectrophotometer
(Hach Company) was used to measure COD, orthophosphate, nitrate, and
ammonia in MWW (highly concentrated sample), and the Gallery Plus
Discrete Analyzer (Thermo Fisher Scientific) was used to measure the
same parameters in the produced effluents (less concentrated samples).
Metals in these effluents were measured by inductively coupled plasma
optical emission spectrometry (ICP-OES) (Agilent 5110 ICP-OES using
the Vertical Dual View configuration and the SPS 4 Auto sampler).
To assess biological contamination, the total plate count (TPC), the
total coliforms, andEscherichia coli (E. coli), were measured; the latter
two were measured using the U.S. EPA-approved Colilert test (Idexx
Laboratories).