Optima 2000 dv system

For the determination of Pb and Cd, samples were further dried in an oven at 105°C for 2–3 days. Both metals were determined at the WPUT in Szczecin. Digestion was performed in an Anton Paar Multiwave microwave oven (Anton Paar Ltd., Hertford, UK). About 1 g samples were weighed and transferred to pressurized quartz vials, into which 5.0 ml 65% HNO₃ and 2 ml 30% H₂O₂ (both Merck Suprapur^TM) were added. Vials were sealed with Teflon plugs, secured in mineralization bomb units, and placed in the microwave oven, with a temperature and pressure control system in each quartz vessel (for more details see [59 ]. Metals were assayed by inductively-coupled argon plasma optical emission spectrometry (ICP-OES) in a Perkin–Elmer Optima 2000 DV system. Lead and Cd detection limits for the system were 0.1 and 1.0 μg/L respectively.
Both of the analytical procedures were checked by determination of Hg, Pb and Cd concentrations in samples of two reference materials: dogfish liver (DOLT-4, Dogfish Liver Certified Reference Material for Trace Metals, Canadian Irradiation Centre, Laval, Quebec) and bovine muscle (8414 NIST, Bovine Muscle Powder, National Institute of Standards and Technology, Canada). Analytical results for the reference materials are presented in Table 2.

The physicochemical and morphological properties of the natural and modified biomass ash samples were evaluated. The elemental composition was analyzed by inductively coupled plasma-optical emission (ICP-OES) spectrometry using a Perkin Elmer Optima 2000 DV system (Perkin Elmer, Waltham, MA, USA). The surface morphology was observed using an S-4800 scanning electron microscope (SEM; Hitachi, Tokyo, Japan) [24 (link)]. Topographic analysis and quantification of the components were performed using a JEM-2010HT transmission electron microscope (TEM; JEOL Ltd., Akishima, Tokyo, Japan) equipped with an energy-dispersive spectrometer (EDS). Functional groups were characterized by Fourier transform-infrared spectrometry (FTIR) using a Spectrum Two™ IR spectrometer (Perkin Elmer) in the range 4000–500 cm⁻¹ [25 (link)]. The specific surface area of the materials was determined by BET method [24 (link)].