# Applications of Graphene-Based Nanomaterials in Environmental Analysis
## 3 Analytical Applications in Environmental Samples
### Applications of GO-Fe\({}_{3}\)O\({}_{4}\)
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**adsorbent** & **Analyte(s)** & **Applications** & **Sample Preparation** & **Analytical Technique** & **LODs** & **EF 1** & **Reference** \\ \hline G & Co(II), Ni(II) & Tap, river and sea & SPE & FAAS & 0.36, 0.51 ug/L & 200 & [59] \\ GO-silica & Mn(II), Co(II), Ni(II), Cu(II), Pb(II) & Well, pond and lake water & HF-SPME & ICP-MS & 7.5, 0.39, 20, 23, & 10 & [60] \\ G & Sulfonylurea herbicides & Environmental water samples & SPE & UHPLC-MS & 0.28-0.53 ng/L & N/R 2 & [61] \\ GO & Mn(II), Fe(III) & Tap, mineral, river & SPE & FAAS & 0.145, & 325 & [62] \\ GO-silica & Cu(II), Pb(II) & Mineral, waste and sea water & SPE & FAAS & 0.084, 0.27 ug/L & 200–250 & [63] \\ GO-EDA & Fe(III), Co(II), Ni(II), & Waste water from industry & d-uSPE & ED-XRF & 0.08, 0.06, & N/R & [64] \\ GO & Co(II), Ni(II), Cu(II), & Waste water from industry & d-uSPE & ED-XRF & 0.5, 0.7, 18, 1.5, & N/R & [65] \\ GO & Zn(II), Pb(II) & Industry & d-uSPE & ED-XRF & 1.4 ug/L & 250 & [66] \\ GO & Co(II), Ni(II) & Water and spring & SPE & FAAS & 0.25, 0.18 ug/L & 250 & [66] \\ GO & Cr(III), Co(II), Ni(II), & Environmental water samples & d-uSPE & ED-XRF & 0.07–0.25 ug/L & N/R & [67] \\ GO-Gly & Cr(III), Cu(II), Zn(II) & estuarine and lake water & d-uSPE & ED-XRF & 0.15, 0.07, & 1575, 890, & [68] \\ GO-S & Cu(II), Zn(II), Pb(II), & Lake, river, mineral, spring and sea water & & 0.08 ug/L & 810 & [68] \\ GO-S & Cr(III), Cd(II), Cr(III) & Lake, river, mineral, spring and sea water & & & & & \\ GO & Pb(II), Cd(II), Cr(III) & River water & CHd-uSPE & ETAAS & 0.035, 0.005, & 14.7, 16.1, & [70] \\ GO-MWCNT & Cr(III), Fe(III), Pb(II), & Wastewater & SPE & ICP-OES & 0.38 ug/L & 75 & [71] \\ GMeS & Sulfonamides & Lake water & SPE & HPLC & 0.10–0.29 ug/kg 3 & 96-99 & [72] \\ GO-TTC & Pb(II), Cu(II) & Sea water & SPE & FAAS & 0.32, 0.13 ug/L & 83.3 & [73] \\ GO-sponges & Methylene blue & Wastewater & N/R & UV-vis & N/R & N/R & [74] \\ GO-MMT/SA & Methylene blue & Wastewater & N/R & UV-vis & N/R & N/R & [75] \\ \hline \hline \end{tabular}  
* EF = Enrichment Factor, 2 N/R = Not Reported., 3 Only the Limit of Quantification (LOQ) was reported.  
\end{table} 
Table 1: Recent applications of graphene-based nanomaterials in environmental analysis. of the three sulfonamides were between 0.05-0.10 \(\upmu\)g/mL and the recoveries where in the range of 67.4-119.9%. In another study, [PERSON] et al. [79] investigated the adsorption mechanism and the pre-concentration of sulfonamides by using a porphyrin-functionalized mGO nanocomposite from environmental water samples, determined once again by HPLC-DAD. The mechanism was investigated and predicted by altering the value of the pH, so as to activate the hydrogen of the porphyrin ring, to negatively charge the material when it was synthesized and then exploit the electrostatic interactions between the adsorbent and the positively charged sulfonamides at pH 4. This speculation was validated with the Langmuir isotherm. This proposed method exhibited 0.2 \(\upmu\)g/mL LOD and 83.7-116.7% recoveries. [PERSON] et al. [80] prepared mercapto-grafted GO-magnetic chitosan (GO-MC) as a new biosorbent for the extraction and preconcentration of mercury ion from different water samples. For the synthesis of GO-MC composite, a chitosan solution of 2% \(w/v\) was formulated by dissolving 2 g of chitosan powder into 100 mL of 2% \(v/v\) CH\({}_{3}\)COOH under ultrasonication and stirring for 2 h at room temperature. Next, 0.6 g of the MNPs were added into the chitosan solution and the mixture was agitated for another 2 h. Then, 15 mL of glutaraldehyde and 1.5 g of GO were put into the flask.