Electronic Supporting Materials

Electronic Supporting materials

Carbon-coated Fe3O4 nanoparticles with surface amido groups for magnetic solid phase extraction of Cr(III), Co(II), Cd(II), Zn(II) and Pb(II) prior to their quantitation by ICP-MS

Mohamed A. Habilaa, Zeid A. ALOthmana, Ahmed Mohamed El-Toni b, c, Saad A. Al-Tamrah a, MustafaSoylakd, *, JoselitoPuzonLabisb

a Chemistry Department, College of Science, King Saud University, Riyadh-11451, Kingdom of Saudi Arabia

bKing Abdullah Institute for Nanotechnology, King Saud University, Riyadh 11451, Saudi Arabia

cCentral Metallurgical Research and Development Institute, CMRDI, Helwan 11421, Cairo, Egypt

dErciyes University, Faculty of Sciences, Department of Chemistry, 38039- Kayseri-Turkey

*Corresponding author. Fax number: +903524374933, E-mail:

Fig. S1.Calibration Curve for Cr(III), Co(II), Zn(II), Cd(II) and Pb(II) determination by ICP-MS

Fig. S2. The EDS of carbon-coated Fe3O4 magnetic nanoparticles

TGA analysis of carbon-coated Fe3O4 magnetic nanoparticles

TGA analysis of the Fe3O4, polyacrylamide and carbon-coated Fe3O4 magnetic nanoparticlesare shown in Fig.S3. For the Fe3O4 nanoparticles, TGA analysis showed quite stability during increasing the calcination temperature. On the other hand, polyacrylamide possessed a significant weight loss between 300°C and 600°C due to the burning out of the polymer structure (depolymerization). For the carbon-coated Fe3O4 magnetic nanoparticles, the TGA analysis showed a weight loss between 400-600°C, this weight loss is more significant than Fe3O4 nanoparticles and less than that of polyacrylamide alone. This may be due to the organic nature of the polyacrylamide, which is completely decomposed with heat while ash is remained in case of Fe3O4. The weight loss in case of amide-decorated Fe3O4 magnetic adsorbent can be attributed to the decomposition of carbon and amide structures around the Fe3O4 nanoparticles.

Fig. S3 TGA for (a) Fe3O4, (b) polyacrylamide and (c) carbon-coated Fe3O4 magnetic nanoparticles

Surface area and porosity of carbon-coated Fe3O4 magnetic nanoparticles

Fig. S4 (A) Nitrogen adsorption/desorption isotherms and (B) pore size distribution measured at 77 K for carbon-coated Fe3O4 magnetic nanoparticles.

Nitrogen adsorption/desorption isotherm measured at 77 K for amide-decorated Fe3O4 magnetic adsorbent is shown in Fig. 5A. The isotherm exhibited the type IV curve; this may be due to the presence of holes and cavities within the carbon layer as it can be seen in SEM (Fig. 1b). The pore size distribution (Fig. 5B) showed multiple pores at 3.6, 4.9 and 7.9 nm. However, larger pores at 4.8 and 7.9 could be considered as cavity appearing into SEM micrographs. On the other hand, BET surface area, and total pore volume 2.540 m².g-1, 0.006 cc g-1, respectively. However, despite the obtained isotherm was characteristic for porous materials but the obtained values for textural properties ofamide-decorated Fe3O4 magnetic adsorbent suggested that textural properties will not be the governing factor for adsorption of heavy metal cations.

Optimization of the mag-SPE

Fig. S5 Effect of pH on the recovery percentage of analytes (N=3).

Fig. S6Effect of sample volume on the recovery percentage of analyte elements (N=3).

Table S1. Effect of eluent type and concentration on the recovery of analytes (N=3).

Eluent / Recovery (%)
Cr(III) / Co(II) / Cd(II) / Zn(II) / Pb(II)
Nitric acid (1 M) / 85±1.7 / 70±0.9 / 68±2.1 / 81±0.6 / 82±0.5
Nitric acid (2 M) / 100±0.8 / 99±0.5 / 99±0.4 / 110±0.5 / 97±2.0
Hydrochloric acid (2 M) / 92±0.4 / 51±0.5 / 51±1.8 / 62±2.4 / 74±1.9
Hydrochloric acid (3 M) / 37±1.2 / 57±0.1 / 56±1.2 / 64±0.4 / 29±1.3
Acetic acid (2 M) / 72±1.3 / 34±1.0 / 35±1.5 / 43±0.8 / 68±1.0
Acetic acid (3 M) / 82±0.4 / 58±1.0 / 59±1.1 / 65±1.6 / 83±2.6