Toc vcsh analyzer

Samples to determine dissolved organic carbon (DOC) concentrations were collected at each depth and processed as previously described [11 (link)] using a Shimadzu TOC-V_CSH analyzer [40 ]. To determine dissolved free taurine and dissolved free amino acid (DFAA), 5 mL water samples were collected. Water samples were taken from the 100-mL polycarbonate flasks with 20-mL syringes and gently filtered through pre-rinsed 0.2 μm pore-size Acrodisc filters (25 mm; Pall, Supor membrane) into pre-combusted (at 450 °C for 4 h) glass vials and subsequently stored at − 20 °C until further analysis. Analysis were performed using high-pressure liquid chromatography (HPLC) and fluorescence detection after pre-column ortho-phthalaldehyde derivatization as described in Clifford et al. [11 (link)]. Concentrations of taurine and 19 DFAA species were measured. The LOD (limit of detection), LOQ (limit of quantification), the linearity (R²), and the recovery (%) for taurine and the DFAA species measured are given in Table S1.

The total organic content (TOC) of the water of Sungai Klah (SK) hot spring was analyzed using the APHA5310 B high-temperature combustion method [11] . The sample was vaporized at 680°C in a heated chamber packed with oxidative catalyst. The generated CO₂ was then analyzed using a Shimadzu TOC-VCSH analyzer (Kyoto, Japan). The analyzer measured two paths, one for total carbon (TC) and one for inorganic carbon, and the TOC was determined by calculating the difference between the two values.

Phase solubility studies of cabreuva EO with HP-β-CD were investigated by TOC analysis using a Shimadzu TOC-VCSH analyzer. It is based on the production of carbon dioxide (CO₂) following oxidation of organic compounds. CO₂ is then detected using a high-sensitivity infrared gas analyzer (NDIR). First, TOC was measured for the CD solution (TOC_CD). Then, the amount of EO in the filtrate was calculated using the following equation: TOC_EO = TOC_T − TOC_CD, where TOC_T is the TOC value obtained for the filtrate by the TOC analyzer. Results were reported in g/L of organic carbon. The solubility of EO was determined from standard curves constructed with known EO concentrations.

Soil water content (SWC) was measured gravimetrically using 10 g of fresh soil by oven-drying at 105°C for 24 h. Soil pH was determined in a 1:2.5 air-dried soil:water suspension (w:v) using a pH meter (F-71G, LAQUA, HORIBA, Japan). Soil ammonium N (NH₄⁺-N) and nitrate N (NO₃^–-N) were extracted by 1 M KCl from 20 g fresh soil samples and detected using the indophenol blue and dual wavelength (220 nm and 275 nm) colorimetric methods (UV-6000, China), respectively. Soil total organic carbon (TOC) was analyzed using an external heating method with concentrated sulfuric acid and potassium dichromate (H₂SO₄-K₂Cr₂O₇). To examine the contents of soil total N (TN) and total phosphorus (TP), semi-micro Kjeldahl digestion was carried out followed by indophenol blue and molybdenum antimony blue colorimetric methods, respectively. Soil dissolved organic carbon (DOC) and N (DON) were extracted with 0.5 M K₂SO₄ solution and measured using a TOC analyzer (Shimadzu TOC-VCSH Analyzer, Kyoto, Japan).

In order to evaluate the efficiency of the photocatalytic procedure, total organic carbon (TOC) on filtered suspensions (0.22 μm), was evaluated by a Shimadzu TOC V-csh Analyzer equipped with a non-dispersive infrared detector. Ion chromatography (Metrohm) was also used, equipped with an automatic sampler was used for the determination of NO₂⁻, NO₃⁻, and Cl⁻ ions. The analytical column used was a Metrosep A Supp 4 (250 × 4.0 mm) with 9 μm particle size. The eluent used was Na₂CO₃ 1.8 mM-NaHCO₃ 1.7 mM with a flow rate of 1 mL min⁻¹. The total run analysis lasted 20 min, while the injection volume was 20 μL.

Fourier transform infrared spectroscopy (FTIR) analysis was used to explore surface functional groups and was performed with a Perkin Elmer Frontier FTIR Spectrometer equipped with an attenuated total reflectance (ATR) accessory. The crystal structure of the photocatalyst after coating was confirmed by powder X-ray diffraction (XRD) using a Rigaku Mini Flex 600 diffractometer operating with CuKα (λ = 1.54060 Å) radiation at 15 mA and 40 kV with a Ni filter. The analysis range was 20°–80° 2θ with 0.02° step and 1.2 s acquisition for steps. The step time was chosen to adequately obtain a good signal to noise ratio in the mean reflections of (1 0 1) and (1 1 0) planes, which are the two main anatase and rutile planes of TiO₂ [10 (link)]. The substrate was ground by mortar and pestle before XRD analysis. The pore size of the substrate was determined by capillary flow porometry using a Quantachrome Porometer 3 GZ series. The method involves measuring nitrogen gas flow as a function of TMP through the dry and wetted membrane. The pore size is then calculated using the Washburn equation. The wetting liquid was Porofil from Quantachrome Corp., Boynton Beach, FL, USA. The absorbance of the sMO solution at 642 nm was measured by a UV-Visible-Biochrom Libra 522 UV-visible spectrophotometer. Total organic carbon (TOC) of BSA was determined by a Shimadzu TOC-V CSH analyzer.