New Mexico State University Nannochloropsis Positive Collection - Mass spectral peak list/Nannochloropsis Positive Ion Mode - Test No. 1 - 180 degrees C

We illustrate a detailed compositional characterization of hydrothermal liquefaction (HTL) oils derived from two biochemically distinct microalgae, Nannochloropsis gaditana and Chlorella sp. (DOE 1412), for a range of reaction temperature as observed by high-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). The unique capability to unequivocally derive molecular formulae directly from FT-ICR MS-measured mass-to- charge ratio (for several thousand compounds in each oil) shows that lipids are completely reacted/converted for any reaction temperature above 200 degrees C and reveals the formation of non-lipid reaction products with increasing temperature. Specifically, lipid-rich oil is obtained at low reaction temperature (less than 225 degrees C) for both microalgal strains. For positive ion mode, the major lipid components in Chlorella sp. and N. gaditana HTL oils are betaine lipids and acylglycerols, respectively. Acidic species in the HTL oils (observed by negative ion mode) are dominated by free fatty acids (FFA) regardless of reaction temperature. HTL oils obtained at higher-temperatures (ge 225 degrees C) are comprised of a variety of basic nitrogen- and oxygen-containing compounds that originate from protein and carbohydrate degradation at elevated temperature. Similar structural features are observed for the abundant nitrogen heterocyclics between the two strains with slightly lower carbon number for Chlorella sp., overall.我们针对两种生化特性迥异的微藻——微拟球藻（Nannochloropsis gaditana）与小球藻属（Chlorella sp.，DOE 1412）——所衍生的水热液化（hydrothermal liquefaction, HTL）油开展了详细的组成表征，实验借助高分辨电喷雾电离傅里叶变换离子回旋共振质谱（ESI FT-ICR MS）考察了一系列反应温度下的产物特征。该技术可直接通过FT-ICR MS测得的质荷比，精准推导每份油样中数千种组分的分子式，这一独特能力表明：当反应温度高于200℃时，脂质会完全发生反应转化，且随着温度升高会生成非脂质反应产物。具体而言，两种微藻在较低反应温度（低于225℃）下均可获得富脂质油相产物。在正离子模式下，小球藻属与微拟球藻HTL油中的主要脂质组分分别为甜菜碱脂与酰基甘油。无论反应温度如何，HTL油中的酸性组分（通过负离子模式检测）均以游离脂肪酸（free fatty acids, FFA）为主。当反应温度≥225℃时，所得HTL油包含多种源自高温下蛋白质与碳水化合物降解的含氮含氧碱性化合物。两种微藻的产物中均存在大量结构特征相似的氮杂环化合物，整体而言小球藻属产物的碳数略低。