Performance analysis of disposable flow cell for nitrite detection

Abstract

This paper describes the work on the development of disposable micro sample cell for optical spectroscopy. The disposable flow cell is an attractive approach to ensure cleanliness of the sample container and to avoid contamination between samples and residual detergents. The main objective of this work is to develop a disposable flow cell made of Poly-(methyl methacrylate) (PMMA) with polymer optical fiber (POF) connections that is easy to install and has a performance measurement that meets ISO standards. The research involved three stages namely fiber optic preparation, design of the flow cell and analysis of the flow cell design. Chemometrics methods, internal quality control standards, calibration and performance characterization instruments are used for the analysis. The POF fiber performance is described by a linear calibration graph. The Shewhart chart for uncertainty analysis shows no data out of the chart, with mean value meeting the ISO 8258 standard. Comparisons of the calibration to other disposable sample cells show better results in linearity. Chemometrics analysis specified the reading data to be within the warning line in accordance with ISO 8258. Validation of the mathematical model is acceptable as none exceed 95% for the F-test. Average precision and sensitivity are 0.9 and 0.3, respectively. Limit of detection and limit of quantification are 0.07 and 0.25, respectively. Based on the results, the design of a disposable flow cell with POF fiber meets the standards of analysis for sample containers used in a spectrometer.