A high performance liquid chromatography fluorescence method for the analysis of both pyridoxal-5-phosphate and thiamine pyrophosphate in whole blood.

BACKGROUND AND AIMS: The active coenzymes of the water soluble vitamins B1 and B6 (thiamine pyrophosphate (TPP) and pyridoxal-5-phosphate (P5P) respectively) play an important role in numerous bodily functions. The simultaneous analysis of both these analytes is limited to either mass spectrometry based methods or commercial kit suppliers. In this study we developed a novel method for analysis of both TPP and P5P by fluorescence detection. METHODS: Briefly, whole blood samples are precipitated by trichloroacetic acid, and P5P and TPP are both derivatised before separation on a C18-PFP column. The new assay's performance was compared against a recent cycle from an external quality assurance program (RCPAQAP) and the current only existing commercial kit (n = 76). RESULTS: Linearity for both analytes was above 0.99 (r2) up to a concentration range of: 4000 nmol/L (P5P) and 2000 nmol/L (TPP). Precision of the method (intra-day and inter-day) compared against commercial quality control material was below 6% (coefficient of variation). Recovery of both compounds exceeded 90%. Accuracy of the protocol displayed satisfactory results in proficiency testing and had an acceptable level of agreement with the existing current kit method. CONCLUSIONS: Overall, this method provides an economical alternative in routine clinical diagnostic laboratories wishing to perform P5P and TPP analysis.

Sucrose capped gold nanoparticles as a plasmonic chemical sensor based on non-covalent interactions: Application for selective detection of vitamins B1 and B6 in brown and white rice food samples.

We report simple and selective method for detection of vitamins B1 and B6 in brown and white rice samples using localized surface plasmon resonance (LSPR) of sucrose capped gold nanoparticles (AuNPs) as a chemical sensor colorimetrically. Here, detection is based on the color change of AuNPs from pink to blue followed by a red shift of LSPR absorption band in UV-vis region with the addition of vitamins B1 and B6 into the NPs solution. A good linear range was observed in the range of 25-1000 ngmL-1 with detection limit of 8 ngmL-1 for B1 and 50-1000 ngmL-1 with detection limit of 15 ngmL-1 for vitamins B6. The employment of AuNPs for detection of B1 and B6 vitamins in rice food samples showed remarkable abilities in terms of the simplicity, low cost, stability, reproducibility and sensitivity.