Automated Determination of Dissolved Reactive Phosphorus at Nanomolar to Micromolar Levels in Natural Waters Using a Portable Flow Analyzer.
Yao DengPeicong LiTengyue FangYiyong JiangJixin ChenNengwang ChenDongxing YuanJian MaPublished in: Analytical chemistry (2020)
Automated in-field methods for measuring dissolved reactive phosphorus (DRP) over a large concentration range are in high demand for the purpose of better understanding the biogeochemistry of phosphorus in the river-estuary-coast continuum to the open ocean. Here, an automated portable and robust analyzer was described for the determination of nanomolar to micromolar levels of DRP in natural waters. The quantification of DRP was based on classic phosphomolybdenum blue (PMB) chemistry. All the components of the analyzer were computer-controlled using LabVIEW-based laboratory-programmed software. When equipped with a 3 cm Z-type flow cell, the system demonstrated linearity with concentrations up to 12 μmol L-1, a sampling rate of 20 h-1, a limit of detection of 0.11 μmol L-1, and relative standard deviations (RSDs) of 0.4-4.6% (n = 11-576). When a solid-phase extraction cartridge was combined with the analyzer, the PMB formed from the sample was automatically concentrated on the hydrophilic-lipophilic balanced sorbent. The concentrated PMB compound was eluted with NaOH solution and measured in the spectrophotometric system. Under optimal conditions, the nanomolar-level mode afforded a sampling rate of 8 h-1, a limit of detection of 1.7 nmol L-1, and RSDs of 3.0-5.7% (n = 11-120). The system exhibited advantages that included a wide linear range, high sensitivity and reproducibility, low reagent consumption, and insignificant interference from salinity, silicate, arsenate, and other P-containing compounds. The system was successfully applied for discrete sample analysis, fixed site online monitoring, and the real-time underway measurement of DRP in riverine-estuarine-coastal waters.
Keyphrases
- solid phase extraction
- simultaneous determination
- molecularly imprinted
- high performance liquid chromatography
- liquid chromatography tandem mass spectrometry
- liquid chromatography
- tandem mass spectrometry
- deep learning
- gas chromatography mass spectrometry
- sewage sludge
- organic matter
- machine learning
- ultra high performance liquid chromatography
- gas chromatography
- loop mediated isothermal amplification
- high throughput
- real time pcr
- climate change
- label free
- minimally invasive
- heavy metals
- single cell
- mass spectrometry
- microbial community
- cell therapy
- high resolution mass spectrometry
- high resolution
- stem cells
- quantum dots
- mesenchymal stem cells
- neural network
- solid state