700 series

Arsenic halogenide concentrations in lung tissues were analyzed using inductively coupled plasma-optical emission spectrometry (ICP–OES, Agilent Technologies, 700 Series, Belgium). Tissues were oven-dried and digested with 70–71% HNO₃ in a heat block. Prior to analysis, lung samples and dried Sargassum fusiforme were diluted 1:10 in 1% nitric acid. Concentrations were measured using a standard calibration curve (NIST Spinach 1570a).

XRD measurements were carried out on a Rigaku D/MAX 2550 diffractometer with Cu Ka radiation (l = 1.5418 Ǻ). Scanning electron microscope (SEM) images were acquired on a Hitachi S-4800 SEM operating at an accelerating voltage of 3 kV. TEM images were acquired on a JEM-2100F equipped with operated at 200 kV. The chemical composition was obtained by X-ray photoelectron spectroscopy (XPS, Thermo ESCALAB 250Xi) with Mg Kα radiation source (hν = 1253.6 eV). The position of the C 1 s peak at 284.6 eV was employed to be a calibration reference to determine the accurate binding energies (±0.1 eV). The deconvolution of the Ni, Mo, and N was performed through a software XPSPEAK version 4.1. ICP-OES analysis was recorded on Agilent 700 Series instrument.

A vortex mixer from Velp Scientifica in Italy was used for blending the solutions of surfactant, fuel oil, nitric acid, and xylene to form a homogenous mixture. A controlled water bath from Lab Tech (Sep Scie) manufactured in Korea was used to break the emulsions at 80 ± 2 °C. To ensure maximum phase separation, the tabletop centrifuge branded, NEYA16R from India was used. The extracted metals in an aqueous solution were analysed using Agilent Technologies 700 Series inductively coupled plasma-optical emission spectroscopy (ICP-OES). Sample uptake for the ICP-OES was accomplished by using an Agilent Technologies SPS 3 autosampler, and sample introduction was through concentric nebulizer and cyclonic spray chamber. Instrumental parameters were power (1.2 kW), which was maintained at the manufacturer's suggested levels, plasma (Ar) flow rate, nebulizer flow rate, peri-pump speed, and auxiliary gas flow rate, which were maintained at 1.5 L/min, 0.754 L/min, 15 rpm and 15.0 L/min, respectively. The analytical spectral wavelength lines best suitable for the investigated metals were As 188.980 nm, Ba 234.759 nm, Cd 214.439 nm, Cr 206.550 nm, Ni 216.55 nm, Pb 283.30 nm, Sb 217.582 nm, Sn 189.925 nm, Tb 350.914 nm, Te 190.802 nm and V 292.299 nm.

The aerial parts of H. petiolaris plants were collected after a cultivation period of 6 months. The essential oil was extracted by steam distillation from the dried plant biomass using a benchtop scale extractor (Figmay SRL, Argentina). From each site, five samples of floral water (a by-product from distillation) and essential oil were filtered (0.22 µm), and five samples of the plant waste were digested, as mentioned above, to determine Pb concentrations by inductively coupled plasma-atomic emission spectrometry (ICP-OES, Agilent Technologies, 700 series, Belgium).
The H. petiolaris essential oil composition was analyzed in an HP 6890N Series Plus gas chromatograph (Agilent Technologies, Palo Alto, California, EE. UU.), equipped with a model 5973N mass selective detector (Agilent Technologies, Palo Alto, California, EE. UU.) and an HP 6890 Series autoinjector. The separation of the compounds was achieved using an HP-5 MS capillary column (30 m × 0.25 mm I.D., 0.25 m film thickness, and 5% phenylmethylsiloxane), supplied by J&W Scientific (Folsom, CA, USA). Based on a mass scan range of 50–550 atomic mass units (AMU) with SCAN mode, the retention times of the compounds were determined by comparing the MS fragmentation pattern of the standards and the National Institute of Standards and Technology (NIST) 2.0 GC–MS library.

During harvest, roots were incubated in 10 mM Pb(NO₃)₂ for 15 min at 4 °C, to exchange surface-bound metals, and subsequently rinsed in distilled water. Harvested leaves were rinsed with distilled water. Next, samples were dried in an oven at 80 °C, weighed, and digested in HNO₃ (70–71%) and HCl (37%) using a heat block. Prior to analysis, extracts were dissolved in a final solution of 2% HCl. Using inductively coupled plasma optical emission spectrometry (ICP-OES; Agilent Technologies 700 Series, Santa Clara, CA, USA), Cd concentrations were quantified. Standard (trace elements in cabbage powder, No. 679, Standard Reference Material) samples were included for reference purpose.

Plant survival, biomass development, and vegetation cover were weekly monitored during the field trial. After 6 months, when reaching the flowering phase, plants were harvested. Roots were washed three times with sterile water to remove any soil particles. Shoots, flowers, and roots were oven-dried (60 °C for 1 week), weighed, digested with 70% HNO₃ in a heat block, and dissolved in 5 mL of 2% HCl, according to the US EPA 3050B Acid Digestion of Sediments, Sludges, and Soils protocol [41 ]. Trace element concentrations were determined using inductively coupled plasma-atomic emission spectrometry (ICP-OES, Agilent Technologies, 700 series, Belgium). Blanks (only HNO₃) and standard references (NIST Spinach 1570a) were included.
The BAF was calculated according to Rafati (2011) [42 (link)] using the ratio of element concentration in the plant roots to the soil for the “BAF roots”, the ratio of total element concentration in plant shoots (stem + leaves) to the soil for the “BAF shoots”, and the ratio of element concentration in the plant flower heads to the soil for the “BAF flower heads”. The TF was calculated according to Padmavathiamma and Li (2007) [43 (link)] using the ratio of element concentrations in the areal parts of the plants (shoots + flower heads) to the roots.

Harvested leaves were rinsed with distilled water to remove any residual metals. Roots were submerged for 15 min in 10 mM Pb(NO₃)₂ at 4 °C, to exchange surface-bound metals, and rinsed in distilled water. Prior to analysis, samples were oven-dried at 80 °C and digested in HNO3 (70–71%) and HCl (37%). Cadmium concentrations were determined via inductive coupled plasma-optical emission spectrometry (ICP-OES; Agilent Technologies 700 Series, Santa Clara, CA, USA). For reference purposes, blank (HNO₃) and standard (trace elements in spinach, 1570a, Standard Reference Material) samples were included.