A flow–batch luminometer

The traditional flow chemiluminescence (CL) systems typically use flow cells in spiral shape mounted in front of a photomultiplier tube (PMT). The sample is transported by using carrier fluids, undergoes dispersion, and mixes with reagents and CL reaction occurs before reaching the flow cell. As a consequence, the maximum of the chemiluminescence intensity is not exploited and the sensitivity is significantly diminished. In this work, these drawbacks were overcome by using a flow–batch approach and a large area silicon photodiode instead of PMT in order to build a simple and automatic luminometer for CL measurements. The feasibility of the proposed flow–batch luminometer was demonstrated in the determination of vitamin B 12 in injection ampoules, yielding limits of detection and quantification (0.11 and 0.36 μg L − 1 , respectively), recovery rates (between 97.8 and 102.1%), relative standard deviations (RSD − 1 ). Thus, it was possible to both project and build a simple, flexible, versatile and automatic luminometer, while keeping the excellent characteristics of the previous flow–batch analyzer such as: low reagent and sample consumption and minimal waste generation.