Field-deployable system for the detection and measurement of micronutrients

Abstract

Micronutrient deficiency is a global problem affecting billions of people world-wide. A lack in any of vitamin A, zinc, iron, folic acid or iodine can result in major health defects which can greatly reduce quality of life. While nutrient supplementation can reduce these deficiencies, other diseases can also occur when nutrient intake is too high. Although accurate systems exist to measure micronutrient status, they are unsuitable for wide scale studies in developing countries due to various drawbacks. In particular, tests are usually specific (capable of analyzing only one, or at most 2 nutrients), expensive, cumbersome and time consuming. To solve these issues, in this work, a compact system capable of measuring multiple nutrients quickly is developed. Initial work focused on developing a proof-of-concept. Here, a laboratory scale mass spectrometer, Low Temperature Plasma ionization source, and multivariate analysis were combined to create a new system, Plasma Pencil Atmospheric Mass Spectrometry (PPAMS). PPAMS was used to study sample matrices containing nutrients at three different levels spanning the blood range. Individual nutrients were studied by varying single nutrients and holding the other nutrients constant. In these cases, principal component analysis was capable of classifying data based on nutrient concentration by performing a cube root transformation on the data. The spectra, however, could not be compared for sample data collected on different days due to the appearance of new contamination peaks, caused by using shared equipment. With detection differences achieved on a laboratory scale instrument, a compact MS, the Advion Expression, was purchased. After system optimizations, individual peaks indicative of nutrient content were observed for Vitamin A, Iron and Zinc. Furthermore, individually quantifying Vitamin A and Zinc was achieved by constructing mathematical models to predict independent data sets in controlled samples at blood levels. The remaining nutrients, and multi-nutrient samples, however, could not be accurately quantified. Overall, PPAMS has been shown to be capable of detecting and quantifying select nutrients at nanogram quantities, even in the presence of a high salt background. Furthermore, with additional system improvements and advances in technology, this method may be capable of simultaneously measuring all 5 micronutrients.