Simple and Sensitive Method for Pyrroloquinoline Quinone (PQQ) Analysis in Various Foods Using Liquid Chromatography/Electrospray-Ionization Tandem Mass Spectrometry

• DOI: 10.1021/jf070483r
• Publication Date: 2007-08-09T11:00:53Z
• Authors: Natsumi Noji; Takemichi Nakamura; Nobutaka Kitahata; Katsuhiko Taguchi; Toshiaki Kudo; Shigeo Yoshida; Masafumi Tsujimoto; Tamizi Sugiyama; Tadao Asami
• Keywords: 2. Zero hunger; Spectrometry, Mass, Electrospray Ionization; 0303 health sciences; 03 medical and health sciences; PQQ Cofactor; Plants, Edible; Sensitivity and Specificity; Chromatography, High Pressure Liquid; Food Analysis

Pyrroloquinoline quinone (PQQ) is believed to be an important factor for mammalian growth and development and has, therefore, been declared a vitamin by some researchers. However, this issue remains controversial, and from a nutritional viewpoint, accurate determination of PQQ levels in a variety of foods is very important. Here, we describe a simple, highly sensitive, and highly selective method for quantitative analysis of PQQ. Liquid foods or aqueous extracts of solid foods were analyzed using high-performance liquid chromatography (HPLC) combined with electrospray-ionization (ESI) tandem mass spectrometry (MS/MS). (15)N-labeled PQQ was added to the samples as an internal standard. Quantitative analyses of PQQ were performed by multiple reaction monitoring (MRM) with LC/MS/MS. Free PQQ was detected in almost all food samples in the range 0.19-7.02 ng per g fresh weight (for solid foods) or per mL (liquid foods). This method will enable the rapid and simple determination of PQQ levels in many samples.