Transparent Cross-Flow Platform as Chemiluminescence Detection Cell in Cross Injection Analysis

This work presents the use of a transparent 'Cross Injection Analysis' (CIA) platform as a flow system for chemiluminescence (CL) measurements. The CL-CIA flow device incorporates introduction channels for samples and reagents, and the reaction and detection channels are in one acrylic unit. A photomultiplier tube placed above the reaction channel detects the emitted luminescence. The system was applied to the analysis of (i) Co(II) via the Co(II)-catalyzed H₂O₂-luminol reaction and (ii) paracetamol via its inhibitory effect on the catalytic activity of Fe(CN)₆^3- on the H₂O₂-luminol reaction. A linear calibration was obtained for Co(II) in the range of 0.002 to 0.025 mg L^-1 Co(II) (r² = 0.9977) for the determination of Co(II) in water samples. The linear calibration obtained for the paracetamol was 10 to 200 mg L^-1 (r² = 0.9906) for the determination of pharmaceutical products. The sample throughput was 60 samples h^-1. The precision was ≤4.2% RSD. The consumption of the samples and reagents was ca. 170 µL per analysis cycle.