Table 4 Average concentration of organic acids detected in dilute acid pretreated Miscanthus hydrolysate and relative standard deviation (RSD) of intra-day and inter-day repeatability
Intra-day | Inter-day | |||
|---|---|---|---|---|
Compound | mean (μg/ mL) | RSD (%) | mean (μg/ mL) | RSD (%) |
Oxalic acid | 48.4 | 2.0 | 47.8 | 4.3 |
cis-Aconitic acid | 7.2 | 2.0 | 7.4 | 3.4 |
Maleic acid | 11.4 | 3.1 | 11.3 | 1.2 |
Glucuronic acid | 251.9 | 0.4 | 259.5 | 5.4 |
Citric acid | 90.5 | 1.1 | 88.6 | 2.6 |
Galacturonic acid | 607.5 | 0.7 | 581.8 | 3.9 |
Gluconic acid | 218.0 | 2.7 | 215.5 | 1.6 |
Pyruvic acid | 159.5 | 4.3 | 158.2 | 7.9 |
Tricarballylic acid | 64.5 | 1.4 | 63.3 | 7.3 |
Glyoxylic acid | 602.2 | 9.2 | 627.8 | 7.6 |
Malic acid | 92.1 | 0.8 | 81.7 | 11.5 |
Malonic acid | 27.8 | 1.5 | 26.7 | 14.9 |
trans-Aconitic acid* | 98.4 | 1.7 | 103.3 | 6.6 |
Methylmalonic acid | 7.6 | 4.4 | 7.6 | 18.7 |
Succinic acid | 19.0 | 5.8 | 19.8 | 4.8 |
Glycolic acid | 56.0 | 3.3 | 57.8 | 4.0 |
Lactic acid | 31.1 | 4.9 | 38.0 | 7.2 |
Itaconic acid | 5.7 | 5.8 | 6.5 | 13.4 |
Glutaric acid* | 93.8 | 1.8 | 90.1 | 3.9 |
Fumaric acid* | 105.8 | 2.5 | 103.6 | 2.2 |
2-Hydroxy-2-methylbutyric acid* | 101.4 | 3.2 | 107.4 | 5.7 |
Adipic acid* | 88.6 | 2.7 | 84.1 | 6.1 |
Levulinic acid | 1114.3 | 1.0 | 1071.2 | 4.4 |
2-Furoic acid | 12.2 | 8.8 | 13.1 | 12.9 |