Analytical Chemistry Department, Faculty of Sciences-IVAGRO, University of Cádiz, Agrifood Campus of International Excellence, Post Office Box 40, Pol. Río San Pedro, Puerto Real 11510, Cádiz, Spain.
Analytical Chemistry Department, Faculty of Sciences-IVAGRO, University of Cádiz, Agrifood Campus of International Excellence, Post Office Box 40, Pol. Río San Pedro, Puerto Real 11510, Cádiz, Spain.
J Chromatogr A. 2018 May 25;1551:41-51. doi: 10.1016/j.chroma.2018.04.011. Epub 2018 Apr 5.
A novel extraction technique is proposed in which the Multiple Headspace Extraction (MHE) approach is used in conjunction with Headspace Sorptive Extraction (HSSE) and Gas Chromatography-Mass Spectrometry (GC-MS) detection. The extraction method was developed to determine volatile compounds in macroalgae. Optimization of the extraction parameters was carried out using design of experiments to identify factors that affect the extraction: extraction time, temperature, twister length and amount of sample. The results of the optimization led to an extraction of 2 g of sample using a 20 mm Twister at 66 °C for 180 min. The progression constants (β) were calculated for 43 volatile compounds, 29 of which could be quantified using the method. Linearity was attained with a determination coefficient higher than 0.99 for all studied compounds. Inter-day and inter-twister precisions ranged from 0.22% to 19.01% and from 0.69% to 14.76% respectively, and values below 10% were obtained for the majority of compounds. LOD and LOQ values ranged from the values obtained for diethyl succinate (0.012 μg/L and 0.088 μg/L, respectively) and those obtained for dimethyl sulfide (5.544 μg/L and 40.286 μg/L, respectively). However, for the majority of compounds values obtained were below 1 μg/L (LOD) and 5 μg/L (LOQ). Compounds such as ethyl acetate, hexanal, heptadecane, 2-hexenal, 6-methyl-5-hepten-2-one, dimethyl sulfide, benzyl alcohol, beta ionone, or beta cyclocitral, among others were correctly determined in three species of macroalgae: Ulva sp., Gracillaria sp. and Enteromorpha sp.
提出了一种新的提取技术，该技术结合顶空吸附萃取（HSSE）和气相色谱-质谱联用（GC-MS）检测，采用多顶空萃取（MHE）方法。该提取方法用于测定大型藻类中的挥发性化合物。通过实验设计优化提取参数，以确定影响提取的因素：提取时间、温度、涡旋长度和样品量。优化结果得出，使用 20mm 涡旋，在 66°C 下提取 180min，可提取 2g 样品。计算了 43 种挥发性化合物的推进常数（β），其中 29 种可以使用该方法定量。所有研究化合物的线性相关系数均高于 0.99。日内和涡旋间精密度分别在 0.22%至 19.01%和 0.69%至 14.76%之间，大多数化合物的精密度均低于 10%。LOD 和 LOQ 值的范围分别为琥珀酸二乙酯（0.012μg/L 和 0.088μg/L）和二甲基硫（5.544μg/L 和 40.286μg/L）的值，而对于大多数化合物，LOD 和 LOQ 值均低于 1μg/L 和 5μg/L。在三种大型藻类中，如乙酸乙酯、己醛、十七烷、2-己烯醛、6-甲基-5-庚烯-2-酮、二甲基硫、苯甲醇、β-紫罗兰酮、β-环柠檬醛等化合物被正确测定。
