Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Research Center on Chemistry for Development of Health Promoting Products from Northern Resources, Chiang Mai University, Chiang Mai 50200, Thailand.
Molecules. 2022 Jun 20;27(12):3957. doi: 10.3390/molecules27123957.
At present, there is no colorimetric method for the quantitation of the aroma compound 2-acetyl-1-pyrroline (2AP). A novel colorimetric method was developed for the determination of 2AP content using chromium hexacarbonyl (Cr(CO)) as a reagent. The reaction of synthetic 2AP with chromium hexacarbonyl reagent solution in the presence of light produced a green product with an absorption maximum (λ) at 623 nm. GC-MS was used to confirm the color-change reaction, which showed the loss of 2AP after the addition of Cr(CO). This novel method enables facile and cost-effective determination of 2AP in fragrant rice. A comparative analysis of fragrant and nonfragrant rice grain extracts showed that no color-change reaction occurred with the nonfragrant rice sample. A limit of detection (LOD) of 2.00 mg L was determined by method validation with an effective linear concentration ranging from 5.00 to 60.00 mg L of 2AP. The results obtained using the developed colorimetric method were consistent with those obtained by automated static headspace gas chromatography with nitrogen-phosphorus detection (SHS-GC-NPD).
目前，还没有用于定量分析香气化合物 2-乙酰基-1-吡咯啉（2AP）的比色法。本研究开发了一种新的比色法，使用六羰基铬（Cr(CO)）作为试剂来测定 2AP 的含量。在光的存在下，合成的 2AP 与六羰基铬试剂溶液反应生成一种在 623nm 处具有最大吸收（λ）的绿色产物。GC-MS 用于确认颜色变化反应，结果表明加入 Cr(CO) 后 2AP 消失。该新方法可方便且经济有效地测定香米中的 2AP。对香米和非香米籽粒提取物的比较分析表明，非香米样品没有发生颜色变化反应。通过对 2AP 有效线性浓度范围为 5.00-60.00mg/L 的方法验证，确定了检测限（LOD）为 2.00mg/L。用开发的比色法得到的结果与用氮磷检测自动静态顶空气相色谱法（SHS-GC-NPD）得到的结果一致。
