Vista pro ccd simultaneous icp oes

Overnight cultures were diluted 1:100 into GM17 broth with erythromycin if required and incubated until late log phase (OD₆₀₀ ~ 1). Cultures (50 ml) were centrifuged at 5,000 x g (Beckman Coulter, USA) for 10 mins at 4°C and the supernatants were discarded. A second centrifugation was carried out and all media residue was removed by pipette. Cells were subsequently digested with 500μl of 15% HNO₃ at 95°C for 1 hour. After digestion, the mixture was centrifuged at 5000 x g for 30 minutes at 4°C. Thereafter, the supernatant was collected to measure K⁺ content using Vista-Pro, CCD Simultaneous ICP-OES (Varian Inc., USA). The argon gas was ionized and used to create plasma at 7,000–10,000°C and the emission wavelength of 766.491 nm was used for measuring K⁺. Mean ± SEM were calculated based on three biological replicates.

UV-vis absorption spectra were recorded on a Shimadzu UV-1800 spectrophotometer (Kyoto, Japan). Fluorescence spectra were performed on a Hitachi F-7000 fluorescence spectrometer (Tokyo, Japan). X-ray photoelectron spectroscopy (XPS) measurements were carried out using an ESCALAB 250Xi spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). High-resolution transmission electron microscopy (HR-TEM) and energy-dispersive X-ray spectroscopy (EDX) data were obtained on a FEI Tecnai G2 F20 S-TWIN transmission electron microscopy instrument operating at 200 kV (Hillsboro, OR, USA). Electrospray ionization mass spectrometry (ESI-MS) measurements were conducted on a QSTAR elite liquid chromatography-mass spectrometry (LCMS, SCIEX, Toronto, ON, Canada), equipped with a common ESI source. Time-resolved luminescence intensity decay was recorded on a Horiba JY Fluorolog-3 molecule fluorometer (Paris, France), and samples were excited by a 375 nm laser light source. Inductively coupled plasma-optical emission spectrometry (ICP-OES) data were obtained on VISTA-PRO CCD Simultaneous ICP-OES (Varian, Palo Alto, CA, USA). Dynamic light scattering (DLS) was determined using a Nano-ZS90 (Malvern Instruments, Malvern, UK).

The heavy metals were monitored during the experiment. Soil samples were digested with HNO₃ acid for heavy metal quantification analysis according to EPA 3050 B using Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES), VISTA-PRO CCD Simultaneous ICP-OES, Varian, prior, during, and after the treatment. Metals reduction by bacterial cells was calculated as the ratio of ions removal:

Freeze-dried material was used for mineral and vitamin analysis; for this purpose, the products had to be cut into pieces and freeze-dried (EPSILON 2-40; Christ, Osterode am Harz, Germany). Subsequently, the samples were ground with a coffee grinder (KSW 3307, Clatronic International, Kempen, Germany) and stored at +4 °C until analysis. Mineral concentrations were determined using a method adapted from that of Wheal et al. [30 (link)]. Approximately 100 mg of each sample was digested in 4 mL of 65% (v/v) nitric acid and 2 mL of 30% (v/v) hydrogen peroxide for 75 min at 200 °C and 40 bar in a microwave oven (Ethos 660; MWT AG, Heerbrugg, Switzerland). Samples were then made up to 25 mL with distilled water. Mineral concentrations were measured by inductively coupled plasma optical emission spectrometry (Vista-PRO CCD Simultaneous ICP-OES; Varian Inc., Palo Alto, CA, United States). Vitamin analysis of freeze-dried samples was conducted by bilacon (bilacon GmbH, Berlin, Germany, Department of Instrumental Analysis) using standardized procedures of the multi-method for determining water- and fat-soluble vitamins in food by LC-MS/MS (methods: PV-SA-158 and 159, 2019-02).

For elemental analysis, root and shoot samples were harvested separately (~200 mg). Apoplastic cations were desorbed from roots by washing samples in ice-cold 2 mM CaSO₄ and 10 mM EDTA for 10 min followed by 0.3 mM bathophenanthroline disulfonate and 5.7 mM sodium dithionite for 3 min as described by Cailliatte et al. (2010) (link). Samples were washed twice with dH₂O then dried for 48 h at 65 °C and the dry weight recorded. Dried samples were then digested in 2 ml of 65% (v/v) HNO₃ and 0.5 ml of H₂O₂ for 4 h at 95 °C. The digested solution was diluted to 15 ml with ultrapure water and analysed by ICP-OES (Vista-PRO CCD Simultaneous ICP-OES; Agilent Technologies) calibrated with standards: Zn and Fe at 0.2, 0.4, 0.6, 0.8, and 1 mg l^–1 and Mn at 1, 2, 3, 4, and 5 mg l^–1. Soft winter wheat flour was used as a reference material (RM 8438; U.S. National Institute of Standards and Technology) and analysed in parallel with all experimental samples.

Mineral content was taken from leaf tissue samples (2018). Leaf samples of approximately 0.2 g were dried and ground to a fine powder before digestion with 2 mL nitric acid (67–69%, low-metal) and 0.5 mL hydrogen peroxide (30–32%, low-metal) for 12 h at 95°C. Samples were then diluted 1:11 in ultrapure water before analysis with ICP-OES (Vista- PRO CCD Simultaneous ICP-OES; Agilent). Calibration was carried out using standards of Zn, Fe, and Mg at 0.2, 0.4, 0.6, 0.8, and 1 mg L^–1 and Mn and P at 1, 2, 3, 4, and 5 mg L^–1.