## 4 Critical Comparison
The BETsurface area of mMIP was 12.766 m\({}^{2}\)/g. The pore volume of the material was found to be 0.058 cm\({}^{3}\)/g, and the pore width was found to be quite large, equal to 1.752 nm. It was found that the synthesized mMIIP could selectively and efficiently adsorb As(V) species in the presence of competing ions, including Ca\({}^{2+}\), Mg\({}^{2+}\), Cd\({}^{2+}\), Zn\({}^{2+}\), Cu\({}^{2+}\), Mn\({}^{2+}\), Ni\({}^{2+}\) and As(III), and had a high selective As(V) adsorption efficiency; the maximum adsorption capacity for As(V) was quite satisfactory, this being calculated as 7.53 mg/g within the pH 4-6 range. Moreover, molecularly imprinted membranes have been reported for As(V) in water purification and for removing As(III) from realistic samples (hot spring water, urine, and arsenic-based pharmaceutical samples) [85]. In particular, the first prepared molecularly imprinted nanoparticles with precipitation polymerization (60 \({}^{\circ}\)C for 24 h), using MAA and hydroquinone as the functional monomers, EDTAA as the cross-linking agent, AIBN as the initiator, and acetonitrile as the porogen; then, a membrane electrode was constructed by the dispersion of As(III)-imprinted or non-imprinted polymer nanoparticles of THF, adding DNP or DBP as a plasticizer and PVC powder to the mixture. The sensor was used for arsenic determination in some real-life samples. High-level selectivity and a low detection limit were shown for the developed As(III) sensor. The proposed sensor was found to work well under laboratory conditions and showed satisfactory results when used as an approach for the determination of arsenic amounts in a real sample. The selectivity of the developed sensor to As(III) was shown to be satisfactory; however, the lifetime of the sensor needed to be improved. Recently, nanoMIPs, prepared by the templating of fluorescein and As(V) complex in 4-VP-co-EGDMA polymer via molecular imprinting, were reported for As(V) in aqueous solutions. The adsorption capacity of nanoMIPs for As(V) was 49.4 mg/g at pH 7.0 [81]. The nanoMIPs were also tested with real water samples, i.e., groundwater, surface water, and estuary samples, and the adsorption capacity was 40, 36, and 29 mg/L, respectively. The BET surface area of the nanoMIPs was 390 m\({}^{2}\)/g, which is 40% higher compared to the non-imprinted polymers (NIP), and the pore volume was found to be 0.141 cm\({}^{3}\)/g. In addition, the highest surface area was provided by some very recently presented MIPs, i.e., a mesoporous As(V) ion-imprinted polymer (M-IIP) [83], which is 523.9 m\({}^{2}\)/g, for an IIIP@SiO2@Fe3O4, it is 610.99 m\({}^{2}\)/g [82], and for a MAC-As(III)/As(V) complex, 980 m\({}^{2}\)/g. On the other hand, regarding As(III) removal, a pre-polymerization complex of As(III), with 1-vinylimidazole as a ligand [87], offers the most effective, accurate, and specific binding sites for the As(III) ion. In addition, a synthesized ion-imprinted polymer (As(III)-IIP), with As(III) as a template and allythiophene as a functional monomer, exhibited a high percentage removal of 90% [86]. Finally, according to our adsorption-desorption experiments, in order to evaluate the regeneration efficiency of MIPs, we concluded that after 4-10 cycles of regeneration and reuse, as mainly reported elsewhere [81; 82; 83; 84; 87; 88; 89], the loss of initial adsorption capacity was slight. There are two studies showing that the regenerated imprinted polymers were effective for 20-25 cycles [32; 80]. In most cases, an acidic solution was used as the desorption agent, i.e., HCl [80; 83; 84; 87] and HNO3 [81; 89], and only in a few cases was NaOH [88] or EDTA [82] used.