## 4 Discussion
Therefore, the scan rate should be selected to provide the optimal balance between Faradic and non-Faradic current. Measuring CV at low scan rates (e.g., 5 mV/s, 10 mV/s) has the advantage of a low non-Faradic current, but a longer scan exposes the electrode to excessive fouling. In contrast, high scan rates (e.g., 500 mV/s) provide high current with low resistivity in a shorter time frame. However, the large surface of the conventional electrode (2-3 mm) can cause signal distortion at the high scan rate, and so this approach is only suitable for use with microelectrodes [85]. The most commonly used scan rate in this review was 100 mV/s, but there is no evidence provided to support this. There is contrary evidence indicating that the CV sensitivity to ascorbic acid improves with higher scan rate [30]. Individual samples may, therefore, need to be tested with different scan rates, as a higher scan rate might be required to assess samples with a minute concentration of antioxidantsto improve sensitivity. Additionally, by analyzing the sample using different scan rates, [PERSON] et al. were able to selectively detect and estimate homocysteine and glutathione in the presence of cystine by taking advantage of the difference in reaction rates between homocysteine, glutathione and catechol, an essential step in improving the selectivity of CV in a complex biological specimen [93]. This issue remains largely unexplored in biological samples. Temperature and pH are inter-related and should be controlled close to physiological values for the measurement of biological samples [94,95]. Given the limited evidence available from the current literature, it is strongly recommended that these variables should be measured and controlled. Overall, precise control of all possible parameters, electrode design and processing of samples are required to improve the consistency and sensitivity of the technique. We believe that the field would benefit greatly from standardized experiment design and reporting conventions to make replication of the experiment easier and allow meaningful comparison between studies. Antioxidants with similar oxidation potential frequently overlap with each other when measured using electrochemical techniques [84]. While this overlap allows an aggregate summary of the LMWA activity of the sample, current CV methods lack the specificity to discriminate individual antioxidants and lack sensitivity to enzymatic antioxidants. This review has shown that HPLC, enzyme, and spiking techniques were used as complementary methods to establish the potential peak-antioxidant connection. Although ascorbic acid and uric acids form the first peak, more work is needed to identify the redox molecules responsible for the second peak [29]. While no studies have reported a method to improve resolution, this limitation is likely to be addressed with the advent of electrode surface modification, altered electron transfer kinetics, and larger electrode surface area [96,97]. This review did not cover studies investigating DPV and SWV. In brief, DPV can improve selectivity when measuring different redox processes when compared with the standard CV. However, DPV also creates practical problems with respect to material stability and cell operation at any larger scale [98]. SWV is the most advanced electrochemical technique, with its advantages including increased sensitivity, short analytical time and the ability to reject non-Faradic current [99]. However, due to its relative complexity, voltammetric data from SWV are less easy to interpret than standard CV, where in most cases, only the net voltammetric peak is analyzed [100]. Consequently, given that CV is a powerful technique for investigating kinetics and mechanisms of the electrochemical process, it is limited because of the lower sensitivity of analyte detection when compared to SWV [101]. An ideal analytical study should therefore begin by performing a CV scan within a large potential window to explore the nature of redox species and determine the potential for oxidation and reduction.