Abstract Brown algae, Laminaria digitata samples were collected over six-month intervals within a year (January, July and December 2015) and assessed for a range of thermochemical properties. Initial pyrolysis rates using thermo-gravimetric analysis (TGA) were carried out to assess their proximate characteristics, ranging from moisture content (MC) (3.48%–4.10%), volatile content (VC) (56.64–56.23%), char (11.80–12.76%) and fixed carbon (27.87–29.95%). Analysis by pyrolysis gas chromatography–mass spectrometry (Py–GC/MS) identified sixty four compounds present in all samples, twenty which have been previously reported as major pyrolysis products of Laminaria digitata. 1H NMR analysis of sodium alginate fractions extracted from the samples was used to characterise the monad, diad, triad frequencies and average block length of the alginate. Results of the monad frequencies FM (0.36–0.46) and FG (0.54–0.64) are consistent with reported values in literature. The Laminaria digitata alginate also showed values that are in agreement with most reported literature for both diad frequencies, homopolymeric mannuronic (FGG = 0.19–0.25) and guluronic (FMM = 0.33–0.47) blocks with alternating block fractions of (FGM = 0.17–0.21) and (FMG = 0.17–0.21), respectively. The M/G ratio value of 1.17–1.80 has been stated for alginates that can be used to produce soft and elastic gels rather than brittle ones. Furthermore, the computed triad frequencies results are (FGGG = 0.14–0.17, FMGM = 0.11–0.13, FGGM = FMGG = 0.05–0.09) and the average block lengths are (NG = 2.15–2.22 and NM = 2.61–3.85).

中文翻译：

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来自英国海岸的褐海藻、Laminaria digitata 的热化学表征

摘要 一年内（2015 年 1 月、7 月和 12 月）每隔六个月收集褐藻、海带样品，并评估一系列热化学特性。使用热重分析 (TGA) 进行初始热解速率以评估它们的近似特性，范围从水分含量 (MC) (3.48%–4.10%)、挥发物含量 (VC) (56.64–56.23%)、焦炭 (11.80 –12.76%) 和固定碳 (27.87–29.95%)。通过热解气相色谱-质谱 (Py-GC/MS) 分析确定了所有样品中存在的 64 种化合物，其中 20 种以前曾被报道为海带的主要热解产物。从样品中提取的海藻酸钠馏分的 1 H NMR 分析用于表征海藻酸盐的单子、二单元、三单元频率和平均嵌段长度。单子频率 FM (0.36–0.46) 和 FG (0.54–0.64) 的结果与文献报道的值一致。Laminaria digitata 海藻酸盐还显示出与大多数报道的文献一致的二元频率、均聚甘露糖醛酸 (FGG = 0.19–0.25) 和古洛糖酸 (FMM = 0.33–0.47) 块的值，交替块分数为 (FGM = 0.17–0.21) ) 和 (FMG = 0.17–0.21)，分别。海藻酸盐的 M/G 比值为 1.17-1.80，可用于生产柔软和有弹性的凝胶，而不是脆性凝胶。此外，计算的三元组频率结果为（FGGG = 0.14–0.17，FMGM = 0.11–0.13，FGGM = FMGG = 0.05–0.09），平均块长度为（NG = 2.15–2.22 和 NM = 2.61–3.85）。Laminaria digitata 海藻酸盐还显示出与大多数报道的文献一致的二元频率、均聚甘露糖醛酸 (FGG = 0.19–0.25) 和古洛糖酸 (FMM = 0.33–0.47) 块的值，交替块分数为 (FGM = 0.17–0.21) ) 和 (FMG = 0.17–0.21)，分别。海藻酸盐的 M/G 比值为 1.17-1.80，可用于生产柔软和有弹性的凝胶，而不是脆性凝胶。此外，计算的三元组频率结果为（FGGG = 0.14–0.17，FMGM = 0.11–0.13，FGGM = FMGG = 0.05–0.09），平均块长度为（NG = 2.15–2.22 和 NM = 2.61–3.85）。Laminaria digitata 海藻酸盐还显示出与大多数报道的文献一致的二元频率、均聚甘露糖醛酸 (FGG = 0.19–0.25) 和古洛糖酸 (FMM = 0.33–0.47) 块的值，交替块分数为 (FGM = 0.17–0.21) ) 和 (FMG = 0.17–0.21)，分别。海藻酸盐的 M/G 比值为 1.17-1.80，可用于生产柔软和有弹性的凝胶，而不是脆性凝胶。此外，计算的三元组频率结果为（FGGG = 0.14–0.17，FMGM = 0.11–0.13，FGGM = FMGG = 0.05–0.09），平均块长度为（NG = 2.15–2.22 和 NM = 2.61–3.85）。47) 块的交替块分数分别为 (FGM = 0.17–0.21) 和 (FMG = 0.17–0.21)。海藻酸盐的 M/G 比值为 1.17-1.80，可用于生产柔软和有弹性的凝胶而不是脆性凝胶。此外，计算的三元组频率结果为（FGGG = 0.14–0.17，FMGM = 0.11–0.13，FGGM = FMGG = 0.05–0.09），平均块长度为（NG = 2.15–2.22 和 NM = 2.61–3.85）。47) 块的交替块分数分别为 (FGM = 0.17–0.21) 和 (FMG = 0.17–0.21)。海藻酸盐的 M/G 比值为 1.17-1.80，可用于生产柔软和有弹性的凝胶，而不是脆性凝胶。此外，计算的三元组频率结果为（FGGG = 0.14–0.17，FMGM = 0.11–0.13，FGGM = FMGG = 0.05–0.09），平均块长度为（NG = 2.15–2.22 和 NM = 2.61–3.85）。