## 2 Materials and Methods
### Analysis by ICP-MS  
An inductively coupled plasma mass spectrometer (ICP-MS, NexIon 2000 PerkinElmer, Waltham, MA, USA) equipped with a concentric nebulizer, a cyclonic spray chamber and a quartz torch was used. The operational parameters were as follows: 1600 Watt for radio frequency, 15 L/min for plasma gas (Ar), 1.0 L/min for nebulizer gas (Ar), a 50 ms dwell time and 20 sweeps/reading. Rhodium and bismuth added to standard and sample solution by on-line mixing were used as internal standards. The following elements/isotopes were detected: \({}^{107}\)Ag, \({}^{27}\)Al, \({}^{75}\)As, \({}^{138}\)Ba, \({}^{8}\)Be, \({}^{111}\)Cd, \({}^{59}\)Co, \({}^{52}\)Cr, \({}^{63}\)Cu, \({}^{56}\)Fe, \({}^{202}\)Hg, \({}^{7}\)Li, \({}^{55}\)Mn,\({}^{98}\)Mo, \({}^{60}\)Ni, \({}^{120}\)Sb, \({}^{78}\)Se, \({}^{118}\)Sn, \({}^{88}\)Sr, \({}^{48}\)Ti, \({}^{51}\)V and \({}^{66}\)Zn. The sum of \({}^{206}\)Pb, \({}^{207}\)Pb and \({}^{208}\)Pb were counted together to improve signal sensitivity. To minimize isobaric interference, the kinetic energy discrimination (KED) system was used, employing helium gas (99.9999%) at 3.8 mL/min (Low KED flow) for the determination of Co, Cu, Mn, Se and V, while the rate of 4.8 mL/min (High KED flow) was used for the determination of Al, Cr, Fe and Ti. Matrix effects were cut down by standard additions into the mineralized solution: for each element, 5 different addition levels were used, including the zero level. The addition levels, stated on the basis of a previous semi-quantitative analytical method by ICP-MS, were as follows: Ag, As, Be, Cd, Co, Hg, Li, Mo, Sb, Sn, Ti and V (0.40-2.0-10-40 \(\mathrm{\SIUnitSymbolMicro\SIUnitSymbol  
mountain areas. These results are consistent with another scientific report that observed a TPC ranging from 345.1 to 502.1 mg GAE/kg in multifocal honey from cerana bee (_Apis cerana_) collected from some regions of China [32]. Meanwhile, honey from different locations in Burkina Faso contained different TPC (32.59-100.39 mg GAE/100 g) and TPC values (0.41-8.35 mg QUE/100 mg) [19], related to the different floral types, the geographical origin of the honey, the climatic conditions and the conditions of production and conservation of the honey [33]. In the comparison between honeys collected at different altitudes, the highest phenol content was recorded in hill honey (52.85 \(\pm\) 3.47 mg GAE/100 g; Figure 1), while the lowest was recorded in mountain honey (40.42 \(\pm\) 1.11 mg GAE/100 g; Figure 1). The hill honeys showed significantly higher flavonoid contents (5.21 \(\pm\) 0.55 mg QUE/100 g; \(p\) < 0.001), followed by mountain honeys (4.16 \(\pm\) 0.55 mg QUE/100 g honey), with plain honeys having the lowest content (3.66 \(\pm\) 0.4 mg QUE/100 g honey). The biological activities and nutraceutical properties of honey are also linked to the presence of phenolic substances that play an important role [34,35]. In fact, the antioxidant action of phenolic acids is closely linked to their chemical structure and manifests itself through different mechanisms [36]. The main responsible factors are hydroxyl groups and their substitutions in the aromatic rings [37] that allow for free radicals to be swept away by giving up a hydrogen atom, electrons or metal cations. As reported by [PERSON] et al. [38], the nutraceutical and biological properties are also driven by the binding of these compounds to organic acids and sugars that preserve the structure of the phenols themselves. Oxidative reactions involve numerous substances and are extremely complex; therefore, in order to evaluate the antioxidant capacity of honey, it is recommended to use at least two tests to increase the reliability of the experiment [39,40].