We discovered that pigments including carotenoids and (bacterio)chlorophylls in pigment–protein complexes, membrane fragments, and chlorosomes suspended in water could be injected directly into C₁₈ HPLC and analyzed without any other treatments. We applied this method to LH1-RC and chromatophores of purple bacteria, chlorosomes of green sulfur bacteria, thylakoid membranes of cyanobacteria, and PSII and thylakoid membranes of spinach. HPLC elution profiles and pigment composition were the same as those of the conventional extraction method. The principle of this method might be that samples are first trapped on top of column, followed by the immediate extraction of the pigments with the HPLC eluent and their separation using the C₁₈ column, as usual. In the conventional extraction method, pigments are first extracted with organic solvents, followed by evaporation of the solvents. The dried pigments are then dissolved in organic solvents and injected into C₁₈ HPLC after filtration. The advantages of this method include the preventions of pigment isomerization and oxidation and the possibility of injecting all samples. Its drawbacks include the accumulation of denatured proteins at the top of column, causing increased HPLC pressure. The use of a guard column might solve this problem. Many factors, such as samples, column, and HPLC systems, may affect this method. Nevertheless, we think that some samples can be analyzed using this method.

我们发现，色素-蛋白质复合物，膜碎片和悬浮在水中的叶绿素中的类胡萝卜素和（细菌）叶绿素等色素可直接注入C ₁₈ HPLC中，无需任何其他处理即可进行分析。我们将此方法应用于紫色细菌的LH1-RC和色谱，绿色硫细菌的脂质体，蓝细菌的类囊体膜，菠菜的PSII和类囊体膜。HPLC洗脱曲线和颜料组成与常规提取方法相同。该方法的原理可能是先将样品捕获在柱顶上，然后用HPLC洗脱液立即提取颜料，然后使用C _18进行分离列，照常。在常规提取方法中，首先用有机溶剂提取颜料，然后蒸发溶剂。然后将干燥的颜料溶解在有机溶剂中，过滤后注入C ₁₈ HPLC中。该方法的优点包括防止颜料异构化和氧化，并可以注入所有样品。它的缺点包括变性蛋白质在色谱柱顶部的积累，从而导致HPLC压力升高。使用保护柱可以解决此问题。许多因素（例如样品，色谱柱和HPLC系统）可能会影响此方法。但是，我们认为可以使用此方法分析一些样本。