# Exploring the Bioethanol Production Potential of _Miscanthus_ cultivars
## 3 Results and Discussion  
### Comparison of Lignin Content Using the Klason Method or ABSL Method  
The lignin content of 7 _Miscanthus_ cultivars was analysed using both the Klason method and the ABSL method. In general, lignin determination using the Klason method was higher (25.76-28.66%) than that observed using the ABSL method (21.42-27.78%, Figure 1A). This could be due to the interference of recalcitrant cellulose on the lignin analysis using the Klason method. The highly crystalline nature of the cellulose present in the lignocellulosic matter of _Miscanthus_ might not have completely degraded during the acid treatment and, therefore, would be measured as lignin content in the Klason method as weight loss is the method of quantification. The difference in lignin composition between the two methods was also previously observed in a study of the cell wall polymer for _Miscanthus_ spp. leaves and shoots [19]. The lignin values reported here are significantly higher than that observed by [PERSON] et al. (2011; 9.2-12.6%) [20] and [PERSON] et al. (2020; 15-20%) [14] but are similar to results reported by [PERSON] et al. (2012; 21.4-27.7%) [21] for the _Miscanthus_\(\times\)_sigganteus_ and _Miscanthus sinensis_ genotypes and also by [PERSON] and [PERSON] (2015; 22.3-26.3%) [10]. As shown in Table 2, the lignin content determined using the ABSL method correlated better with the cellulose and hemicellulose analytical results, showing a total carbohydrate content in the range of 94-100%. In comparison, when the lignin content results from the Klason method was used, five out of nine samples showed a total carbohydrate content of over 100%. Determining lignin content using the Klason method has the advantage of producing isolated lignin, which proved suitable for further morphology analysis via scanning electron microscopy. The method also facilitates the analysis of cellulose and hemicellulose contents as the biomass is hydrolys during the lignin analysis process. In comparison with the ABSL method, the Klason method is not suitable for the analysis of a large number of samples. Using the Klason method, the number of samples that can be analysed simultaneously is limited by the capacity of the lab (e.g., availability of heating mantles and lab space). It is a lengthy process as the samples need to be measured as a dry weight; therefore, samples should be dried overnight and weighed a day later. Although the ABSL method uses several reagents, it has a much simpler apparatus set-up than that of the Klason method. The most distinct advantages are the much shorter reaction time and the larger number of samples that can be analysed simultaneously. The ABSL method can be performed in approximately 3 h. This method is also advantageous if only a small quantity of biomass is available as only around 100 mg is used in each analysis compared to the minimum of 1 g required for the Klason method for a reliable result. Figure 1: Lignocellulosic composition of various _Miscantthus_ cultivars: (**A**) lignin content of _Miscantthus_ cultivars using either the Klason method or the ABSL method; (**B**) comparison of cellulose, hemicellulose and lignin of _Miscantthus_ samples harvested in early and late harvests. Data representative of triplicate values.