Nshime Bertil, Koedam James, Stanton Brian, Tran Quynh, Chen Prescott
Amway Research and Development, Analytical Sciences Laboratory, 7575 Fulton St East, Ada, MI 49355.
Amway Research and Development, Quality Assurance Laboratory, 5101 Spaulding Plaza SE, Ada, MI 49355.
J AOAC Int. 2019 Mar 1;102(2):445-450. doi: 10.5740/jaoacint.18-0029. Epub 2018 Sep 18.
The determination of cyanocobalamin (vitamin B12) and biotin has always been challenging because of the lack of a chromophore for biotin and trace level input for vitamin B12 in supplements. Microbiological assay methods are currently used for quantitation. However, these methods are time consuming, may lack specificity, and have high imprecision. Our laboratory developed and validated an LC method for the simultaneous quantitation of vitamin B12 and biotin. This LC method uses a single quadruple mass analyzer to detect biotin and vitamin B12 at 245.10 and 678.29, respectively. The mass analyzer allows for low limits of quantitation (biotin: 1 ng/mL; vitamin B12: 4 ng/mL). Precision results showed that injections are repeatable without the use of an internal standard (RSD < 5%). Single analyst ( = 5: RSD < 3%), within lab ( = 10: RSD < 8%), and multilab ( = 20: RSD < 13%) precision results were also much better than those reported by microbiological assay methods. Linearity was evaluated between 92.00 ng/mL and 9200 ng/mL (² 09916) for biotin and between 4.846 ng/mL and 484.6 ng/mL (² 0.9999) for vitamin B12. The method is accurate between 20 ng/mL and 60 ng/mL for vitamin B12 and between 400 ng/mL and 1200 ng/mL for biotin. The results show a simple, accurate, and precise method for the quantitation of vitamin B12 and biotin. This work demonstrates that single quadrupole mass analyzers can be successfully used to quantify trace level analytes in quality control laboratories.
由于生物素缺乏发色团且补充剂中维生素B12的输入量处于痕量水平，因此氰钴胺素（维生素B12）和生物素的测定一直具有挑战性。目前微生物测定法用于定量。然而，这些方法耗时、可能缺乏特异性且精密度高。我们实验室开发并验证了一种同时定量维生素B12和生物素的液相色谱法。这种液相色谱法使用单四极杆质量分析仪分别在245.10和678.29处检测生物素和维生素B12。该质量分析仪实现了低定量限（生物素：1 ng/mL；维生素B12：4 ng/mL）。精密度结果表明，无需使用内标物进样即可重复（相对标准偏差<5%）。单分析人员（n = 5：相对标准偏差<3%）、实验室内部（n = 10：相对标准偏差<8%）和多实验室（n = 20：相对标准偏差<13%）的精密度结果也远优于微生物测定法报告的结果。生物素在92.00 ng/mL至9200 ng/mL（r² 0.9916）之间以及维生素B12在4.846 ng/mL至484.6 ng/mL（r² 0.9999）之间评估了线性。该方法对维生素B12在20 ng/mL至60 ng/mL之间以及对生物素在400 ng/mL至1200 ng/mL之间是准确的。结果显示了一种简单、准确且精密的维生素B12和生物素定量方法。这项工作表明单四极杆质量分析仪可成功用于质量控制实验室中痕量分析物的定量。
