Automatic measurement of pesticides in drinking water using on-line solid-phase extraction, HPLC and chemometry

Huen, Julien; Gillard, R.; Mayer, Adolf; Baltensperger, Bruno; Kern, H.

doi:10.1007/bf00323942

Cited by 35 publications

(11 citation statements)

References 11 publications

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“…They have great retention of polar solutes because their hydrophobic surfaces contain a relatively large number of active aromatic sites, which allow p -p interaction between sites and solutes. [15] The recoveries using C 18 were greater than 60.0% for PCE, because C 18 usually provides high recoveries for moderately polar solutes with octanol -water partition coefficient (log K ow ) greater than 2. Hence, five sorbents (C 8 , C 18 , PRP-1, PLRP-S, and Bond-Elut Env) were evaluated to find an appropriate sorbent for the enrichment of these compounds.…”

Section: Optimzation Of On-line Spe and Separationmentioning

confidence: 99%

Determination of Tetrachloroethene, Trichloroethylene, and Their Metabolites at Trace Levels in Ground Waters by On‐Line Solid Phase Extraction/HPLC

Chen

Megharaj

Naidu

2004

Journal of Liquid Chromatography & Related Technologies

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On-line solid phase extraction (SPE) coupled with reversed phase high performance liquid chromatography (PRHPLC-DAD) detection was developed for the determination of tetrachloroethene (PCE), trichloroethylene (TCE), and the metabolites [cis-1,2-dichloroethene (cis-DCE), trans-1,2-dichloroethene (trans-DCE)] in ground waters. The PCE, TCE, and their metabolites were directly concentrated and cleaned-up on the cartridge, and separated by a C 18 column with UV at 210 nm. Five sorbents (C 8 , C 18 , PLRP-S, PRP-1, and Bond-Elut Env) were evaluated to concentrate these compounds. The recoveries of the compounds were significantly improved by the addition of 10% (v/v) acetonitrile (ACN) to 885 ORDER REPRINTS the sample before loading. When a 50 mL sample spiked with 1 mg/L was loaded onto PLRP-S sorbent, the recoveries of the compounds ranged from 66.7% to 104.5%. The determination of these compounds was possible with detection limits less than 0.05 mg/L. The method was compared with a gas chromatography (GC) for the determination of TCE, and good agreement was achieved between both methods. The TCE and its metabolites in ground waters were determined from industrial sites in Salisbury, South Australia to characterize the distribution and assess potential remediation of TCE.

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Section: Optimzation Of On-line Spe and Separationmentioning

confidence: 99%

Determination of Tetrachloroethene, Trichloroethylene, and Their Metabolites at Trace Levels in Ground Waters by On‐Line Solid Phase Extraction/HPLC

Chen

Megharaj

Naidu

2004

Journal of Liquid Chromatography & Related Technologies

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“…a in b jn c kn + e ijk (5) where N represents the number of factors actually contributing to fluorescence, x ijk is an element in the 3D fluorescence spectral matrix X, which represents the fluorescence intensity of sample k at an excitation wavelength of i and emission spectrum of j, c kn is an element in the relative concentration matrix C(K × N), a in is an element in the relative excitation matrix A(I × N), b jn is an element in the relative emission matrix B(J × N), and e ijk is an element in the 3D residual matrix E. In order to adapt to the trilinear model, Harshman [31] proposed to adopt the sum of squared residuals (SSR) as the loss function to represent the difference between real and trilinear decomposition data, which can be expressed as:…”

Section: Alternating Trilinear Decompositionmentioning

confidence: 99%

“…Many researchers have proposed many kinds of methods to detect water quality information because water quality has been increasingly paid attention by the world, and the detection technology becomes more urgently needed. Chemical analysis [3], gas chromatography (GC) [4], high-performance liquid chromatography (HPLC) [5,6], and gas chromatography-mass spectroscopy (GC/MS) [7] are common methods for water-quality detection, although they are complex and time-consuming. The concentration of pollutants is generally low after contaminant intrusion takes place in urban water supply systems, and according to the Environmental Health Criteria-EHC 161 [8] and the 'Guidelines for drinking water quality standards in developing countries' [9], the concentration limit of most organic pollutants is below 10 µg/L.…”

Section: Introductionmentioning

confidence: 99%

Morphological Grayscale Reconstruction and ATLD for Recognition of Organic Pollutants in Drinking Water Based on Fluorescence Spectroscopy

Shi

Mao

Cao

et al. 2019

Water

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This paper proposes a morphological grayscale reconstruction method combined with an alternating trilinear decomposition (ATLD) and threshold method based on 3D fluorescence spectroscopy to detect pollutants present at low concentrations in drinking water. First, the morphological grayscale reconstruction method was used to locate the fluorescence peaks of pollutants by comparing the original and reconstructed spectra obtained through expansion. The signal in the characteristic spectral region was then enhanced using an amplification factor. Feature extraction was subsequently performed by ATLD, and the threshold method was used to qualitatively distinguish water quality. By comparing the proposed method with the direct use of the ATLD and threshold method—which is a commonly used feature-extraction method—this study found that the application of the morphological grayscale reconstruction method can extrude characteristics of 3D fluorescence spectra. Given the typical spectral characteristics of phenol, salicylic acid, and rhodamine B, they were selected as experimental organic pollutants. Results illustrated that the morphological grayscale reconstruction with ATLD improved the spectral signal-to-noise ratio of pollutants and can effectively identify organic pollutants, especially those present at low concentrations.

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“…Current off-line analytical techniques for the determination of low concentrations of hydrocarbons in water require a preliminary extraction step to concentrate the target compounds (Anonymous, 1984;Ducreux et al, 1982;Hazel et al, 1997;Huen et al, 1994;Ridal et al, 1997;Shtivel et al, 1985;Sterzenbach et al, 1997;Yang et al, 1995). These methods are highly sensitive but are not generally suited for continuous on-line measurements nor are they especially adapted for in situ measurements.…”

Section: Introductionmentioning

confidence: 99%

ATR-FTIR sensor development for continuous on-line monitoring of chlorinated aliphatic hydrocarbons in a fixed-bed bioreactor

Acha

Meurens

Naveau

et al. 2000

Biotechnol. Bioeng.

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This article describes the continuous on‐line monitoring of a dechlorination process by a novel attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) sensor. This optical sensor was developed to measure noninvasively part‐per‐million (ppm) concentrations of trichloroethylene (TCE), tetrachloroethylene (PCE), and carbon tetrachloride (CT) in the aqueous effluent of a fixed‐bed dechlorinating bioreactor, without any prior sample preparation. The sensor was based on an ATR internal reflection element (IRE) coated with an extracting hydrophobic polymer, which prevented water molecules from interacting with the infrared (IR) radiation. The selective diffusion of chlorinated compound molecules from aqueous solution into the polymer made possible their detection by the IR beam. With the exclusion of water the detection limits were lowered, and measurements in the low ppm level became possible. The best extracting polymer was polyisobutylene (PIB) in the form of a 5.8‐μm thick film, which afforded a detection limit of 2, 3, and 2.5 mg/L (ppm) for TCE, PCE, and CT, respectively. Values of the enrichment factors between the polymer coating and the water matrix of these chloro‐organics were determined experimentally and were compared individually with predictions obtained from the slopes of absorbance/concentration curves for the three analytes. Before coupling the ATR‐FTIR sensor to the dechlorinating bioreactor, preliminary spectra of the chlorinated compounds were acquired on a laboratory scale configuration in stop‐flow and flow‐through closed‐loop modes. In this way, it was possible to study the behavior and direct response of the optical sensor to any arbitrary concentration change of the analytes. Subsequently, the bioreactor was monitored with the infrared sensor coupled permanently to it. The sensor tracked the progression of the analytes' spectra over time without perturbing the dechlorinating process. To calibrate the ATR‐FTIR sensor, a total of 13 standard mixtures of TCE, PCE and CT at concentrations ranging from 0 to 60 ppm were selected according to a closed symmetrical experimental design derived from a 32 full‐factorial design. The above range of concentrations chosen for calibration reflected typical values during normal bioreactor operation. Several partial least squares (PLS) calibration models were generated to resolve overlapping absorption bands. The standard error of prediction (SEP) ranged between 0.6 and 1 ppm, with a relative standard error of prediction (RSEP) between 3 and 6% for the three analytes. The accuracy of this ATR‐FTIR sensor was checked against gas chromatography (GC) measurements of the chlorocompounds in the bioreactor effluents. The results demonstrate the efficiency of this new sensor for routine continuous on‐line monitoring of the dechlorinating bioreactor. This strategy is promising for bioprocess control and optimization. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 68: 473–487, 2000.

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Automatic measurement of pesticides in drinking water using on-line solid-phase extraction, HPLC and chemometry

Cited by 35 publications

References 11 publications

Determination of Tetrachloroethene, Trichloroethylene, and Their Metabolites at Trace Levels in Ground Waters by On‐Line Solid Phase Extraction/HPLC

Determination of Tetrachloroethene, Trichloroethylene, and Their Metabolites at Trace Levels in Ground Waters by On‐Line Solid Phase Extraction/HPLC

Morphological Grayscale Reconstruction and ATLD for Recognition of Organic Pollutants in Drinking Water Based on Fluorescence Spectroscopy

ATR-FTIR sensor development for continuous on-line monitoring of chlorinated aliphatic hydrocarbons in a fixed-bed bioreactor

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