Donaldson Michael
Hallelujah Acres, 1733 Cutler Way, Zillah, WA 98953, USA.
BMC Res Notes. 2012 Sep 24;5:521. doi: 10.1186/1756-0500-5-521.
Plasma total carotenoids can be used as an indicator of risk of chronic disease. Laboratory analysis of individual carotenoids by high performance liquid chromatography (HPLC) is time consuming, expensive, and not amenable to use beyond a research laboratory. The aim of this research is to establish a rapid, simple, and inexpensive spectrophotometric assay of plasma total carotenoids that has a very strong correlation with HPLC carotenoid profile analysis.
Plasma total carotenoids from 29 volunteers ranged in concentration from 1.2 to 7.4 μM, as analyzed by HPLC. A linear correlation was found between the absorbance at 448 nm of an alcohol / heptane extract of the plasma and plasma total carotenoids analyzed by HPLC, with a Pearson correlation coefficient of 0.989. The average coefficient of variation for the spectrophotometric assay was 6.5% for the plasma samples. The limit of detection was about 0.3 μM and was linear up to about 34 μM without dilution. Correlations between the integrals of the absorption spectra in the range of carotenoid absorption and total plasma carotenoid concentration gave similar results to the absorbance correlation. Spectrophotometric assay results also agreed with the calculated expected absorbance based on published extinction coefficients for the individual carotenoids, with a Pearson correlation coefficient of 0.988.
The spectrophotometric assay of total carotenoids strongly correlated with HPLC analysis of carotenoids of the same plasma samples and expected absorbance values based on extinction coefficients. This rapid, simple, inexpensive assay, when coupled with the carotenoid health index, may be useful for nutrition intervention studies, population cohort studies, and public health interventions.
血浆总类胡萝卜素可作为慢性病风险的指标。通过高效液相色谱法（HPLC）对单个类胡萝卜素进行实验室分析既耗时又昂贵，并且不适用于研究实验室之外的使用。本研究的目的是建立一种快速、简单且廉价的血浆总类胡萝卜素分光光度测定法，该方法与HPLC类胡萝卜素谱分析具有很强的相关性。
通过HPLC分析，29名志愿者的血浆总类胡萝卜素浓度范围为1.2至7.4μM。血浆的乙醇/庚烷提取物在448nm处的吸光度与通过HPLC分析的血浆总类胡萝卜素之间存在线性相关性，皮尔逊相关系数为0.989。血浆样品分光光度测定法的平均变异系数为6.5%。检测限约为0.3μM，在不稀释的情况下，线性范围可达约34μM。类胡萝卜素吸收范围内的吸收光谱积分与血浆总类胡萝卜素浓度之间的相关性给出了与吸光度相关性相似的结果。分光光度测定结果也与基于已发表的单个类胡萝卜素消光系数计算的预期吸光度一致，皮尔逊相关系数为0.988。
总类胡萝卜素的分光光度测定法与相同血浆样品的类胡萝卜素HPLC分析以及基于消光系数的预期吸光度值密切相关。这种快速、简单、廉价的测定法，与类胡萝卜素健康指数相结合，可能对营养干预研究、人群队列研究和公共卫生干预有用。
