Multiresidue Determination of Pesticides in Drinking and Related Waters by Solid-Phase Extraction and Liquid Chromatography with Ultraviolet Detection: Interlaboratory Study

Abstract As part of a project funded by the European Commission (EC) for the development and evaluation of multiresidue methods for analysis of drinking and related waters, 17 European laboratories evaluated a method using styrene–divinylbenzene copolymer solid-phase extraction followed by liquid chromatography with diode array detection. The main aim of the study was to evaluate whether the method meets the requirements of EC Drinking Water Directive 98/83 in terms of accuracy, precision, and detection limit for 21 pesticides according to the following requirements: limit of detection, ≤0.025 μg/L; accuracy expressed as recovery, between 75 and 125%; and precision expressed as repeatability relative standard deviation of the method, <12.5%, and as reproducibility relative standard deviation of the method, <25%. Analyses for unknown concentrations were performed with commercial bottled and tap waters. All laboratories were able to achieve detection limits of 0.01 μg/L for all pesticides except pirimicarb (0.02 μg/L). The criteria for repeatability were met for all compounds. Terbutryn in bottled water and carbendazim in tap water did not meet the criteria for reproducibility. In terms of accuracy, the method met the requirements for all pesticides in both matrixes, except for metamitron. However, several compounds (linuron, terbutryn, propazine, metobromuron, and isoproturon) showed recoveries slightly below 75%.

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Determination of Imazaquin Residues in Soil by Solid-Phase Extraction and High-Performance Liquid Chromatography

Journal of AOAC International ◽

10.1093/jaoac/90.2.568 ◽

2007 ◽

Vol 90 (2) ◽

pp. 568-574 ◽

Cited By ~ 4

Author(s):

Chen Xuyan ◽

Hu Jiye ◽

Li Jianzhong

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Solid Phase Extraction ◽

High Performance ◽

Limit Of Detection ◽

Solid Phase ◽

Phase Extraction ◽

Application Rates ◽

Relative Standard ◽

Strong Anion Exchange

Abstract A method has been developed for the quantitation of imazaquin residues in soil. The herbicide was extracted from soil with methanolwater (2 + 1, v/v) and cleaned up by strong anion-exchange solid-phase extraction cartridges. Analysis was performed by using high-performance liquid chromatography with ultraviolet detection. Average recoveries through the method ranged from 90.7 to 100.6%, with relative standard deviation equal to or lower than 6.6%. The limit of detection was estimated to be 0.0015 mg/kg, and the minimum quantitation concentration of imazaquin in soil was 0.005 mg/kg. This method was successfully applied to evaluate imazaquin residue levels in soil and its dissipation rates in a soybean field in the Xisanqi District of Beijing, People's Republic of China. The dissipation study showed that the half life of imazaquin in soil was 10.37 0.0135 days at 3 different application rates.

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Multiresidue Determination of Pesticides in Drinking and Related Waters by Gas Chromatography/Mass Spectrometry after Solid-Phase Extraction: Interlaboratory Study

Journal of AOAC International ◽

10.1093/jaoac/84.5.1420 ◽

2001 ◽

Vol 84 (5) ◽

pp. 1420-1430 ◽

Cited By ~ 4

Author(s):

François van Hoof ◽

Peter van Wiele ◽

Auguste Bruchet ◽

Isabelle Schmitz ◽

Ivana Bobeldiji ◽

...

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Standard Deviation ◽

Solid Phase Extraction ◽

Solid Phase ◽

Tap Water ◽

Bottled Water ◽

Gas Chromatography Mass Spectrometry ◽

Phase Extraction ◽

Relative Standard

Abstract As part of a project funded by the European Commission (EC) for the development and evaluation of multiresidue methods for analysis of drinking and related waters, 15 European laboratories evaluated a method using styrene–divinylbenzene copolymer solid-phase extraction followed by gas chromatography/mass spectrometry. The main aim of the study was to evaluate whether the method meets the requirements of EC Directive 98/83 in terms of accuracy, precision, and detection limit for 22 pesticides according to the following requirements: limit of detection, ≤0.025 μg/L; accuracy, expressed as recovery between 75 and 125%; and precision, expressed as repeatability relative standard deviation of the method of <12.5% and as reproducibility relative standard deviation of the method of <25%. Analyses for unknown concentrations were performed with fortified commercial bottled and tap waters. All laboratories were able to achieve detection limits of 0.01 μg/L for all pesticides except dimethoate and desisopropylatrazine (0.02 μg/L). The criteria for repeatability were met for all compounds except trifluralin, dimethoate, and lindane in bottled water and chlorpyrifos, dimethoate, and lindane in tap water. The criteria for reproducibility were met for all compounds except trifluralin, dimethoate, and lindane in bottled water and pendimethalin, chlorpyrifos, dimethoate, terbutryn, and lindane in tap water. In terms of accuracy, the method meets the requirements for all pesticides in both matrixes, except for lindane in bottled water and lindane and chlorpyrifos in tap water.

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Development of a solid-phase extraction – spectrofluorimetric method for trace glutathione determination

Canadian Journal of Chemistry ◽

10.1139/v11-006 ◽

2011 ◽

Vol 89 (4) ◽

pp. 517-523 ◽

Cited By ~ 2

Author(s):

Ke-Jing Huang ◽

Cong-Hui Han ◽

Ying-Ying Wu ◽

Chao-Qun Han ◽

De-Jun Niu ◽

...

Keyword(s):

Solid Phase Extraction ◽

Limit Of Detection ◽

Solid Phase ◽

Signal To Noise Ratio ◽

Calibration Graph ◽

Extraction Column ◽

Phase Extraction ◽

Selective Reaction ◽

Spectrofluorimetric Method ◽

Relative Standard

A simple and efficient solid-phase extraction – spectrofluorimetric method has been developed to determine glutathione (GSH). Fluorescent probe N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-yl)methyl)iodoacetamide (BODIPY Fl-C1-IA) was used as the derivatization reagent. The procedure was based on a BODIPY Fl-C1-IA selective reaction with GSH to form the highly fluorescent product BODIPY Fl-C1-IA–GSH, using a solid-phase extraction column and spectrofluorimetric determination. The variables affecting analytical performance were studied and optimized. The calibration graph using the preconcentration system for GSH was linear over the range of 1–200 nmol/L with a limit of detection of 0.05 nmol/L (signal-to-noise ratio = 3). The relative standard deviation for six replicate determinations of GSH at the 100 nmol/L concentration level was 3.9%. The method was applied to water samples and average recoveries between 87.5% and 111.5% were obtained for spiked samples.

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Determination of Clopidol Residues in Chicken Tissues by Liquid Chromatography: Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/86.4.685 ◽

2003 ◽

Vol 86 (4) ◽

pp. 685-693 ◽

Cited By ~ 3

Author(s):

Guo-Fang Pang ◽

Yan-Zhong Cao ◽

Chun-Lin Fan ◽

Jin-Jie Zhang ◽

Xue-Min Li ◽

...

Keyword(s):

Liquid Chromatography ◽

Standard Deviation ◽

Relative Standard Deviation ◽

Solid Phase ◽

Collaborative Study ◽

Reversed Phase ◽

Method Performance ◽

Chicken Muscle ◽

Relative Standard

Abstract Eighteen laboratories participated in a collaborative study on the determination of clopidol residues in chicken muscle tissues by liquid chromatography. Of these, results from 16 laboratories which rigorously followed the method were subjected to statistical analysis. The method performance was assessed by all participants using 14 samples of chicken muscle fortified at concentrations ranging from 0.1 to 5.0 mg/kg. In addition, 9 participants each reported results for 6 clopidol-incurred samples in chicken muscle. Test portions were extracted with acetonitrile, and the extracts were purified with alumina and anion exchange resin solid-phase extraction cartridges in sequence. Clopidol was separated by reversed-phase liquid chromatography and quantified at 270 nm. Average recoveries ranged from 81.8 to 85.4%, reproducibility relative standard deviation (RSDR) ranged from 11.9 to 22.6%, and repeatability relative standard deviation (RSDr) ranged from 9.9 to 15.1%. For clopidol-incurred samples at concentrations of 0.100–0.687 mg/kg, the mean determination value range was 0.099–0.659 mg/kg; RSDR was 12.6–19.8%, RSDr was 3.1–8.5%; and HORRAT values were 0.7–1.1. The accuracy and precision of the method are in conformity with the requirements specified by AOAC INTERNATIONAL. The method was adopted Official First Action in April 2003.

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Determination of Niacin in Infant Formula by Solid-Phase Extraction/Liquid Chromatography: Peer-Verified Method Performance–Interlaboratory Validation

Journal of AOAC International ◽

10.1093/jaoac/85.3.654 ◽

2002 ◽

Vol 85 (3) ◽

pp. 654-664 ◽

Cited By ~ 9

Author(s):

Denis E LaCroix ◽

Wayne R Wolf ◽

G William Chase

Keyword(s):

Liquid Chromatography ◽

Standard Deviation ◽

Reference Material ◽

Infant Formula ◽

Solid Phase ◽

Phase Extraction ◽

Relative Standard ◽

Interlaboratory Validation ◽

Extraction Liquid

Abstract This paper reports the results of the interlaboratory peer validation study of AOAC Peer-Verified Method (PVM) 1:2000 for the determination of niacin in infant formula by solid-phase extraction/liquid chromatography. We have used a Data Quality Objectives (DQO) approach to address not only method variability and robustness but also accuracy of data through the use of an appropriate reference material in conjunction with the interlaboratory validation study. Our DQO included the following: (1) statistical agreement of analytical results and quantitative recovery between 2 collaborating laboratories; (2) the repeatability relative standard deviation (RSDr) values and the HORRAT (Horwitz ratio) obtained (1.07), which satisfied the criteria of the Horwitz “limits of acceptability” at the analyte level present; (3) validation of lack of interference; and (4) accuracy agreement within assigned values for a certified reference material. National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1846 Infant Formula, with a certified value of 63.3 ± 7.6 μg/g for niacin content, was used as a test material for collaborative study and accuracy assessment. Niacin values obtained by the originating laboratory were 59.7 ± 4.0 μg/g (95% confidence interval [CI] = 1.4 μg/g with a relative standard deviation [RSD] of 6.7%) and by the peer laboratory were 56.6 ± 6.6 μg/g (95% CI = 4.1 μg/g, with an RSD of 11.7%). Statistical evaluation using the means equivalence test showed that nicotinic acid values obtained by the peer laboratory were equivalent to those values obtained by the originating laboratory. Linear calibration curves and quantitative recovery were obtained. Integration of the PVM process with a readily available certified reference material gives the user confidence in the accuracy of the data generated by the method through traceability to the reference material used.

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Spectrophotometric Determination of Iron(II) after Solid Phase Extraction of Its 2,2′ Bipyridine Complex on Silica Gel-Polyethylene Glycol

Journal of Spectroscopy ◽

10.1155/2013/548345 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 7

Author(s):

Nahid Pourreza ◽

Saadat Rastegarzadeh ◽

Ali Reza Kiasat ◽

Hossein Yahyavi

Keyword(s):

Polyethylene Glycol ◽

Solid Phase Extraction ◽

Silica Gel ◽

Limit Of Detection ◽

Solid Phase ◽

Extraction Procedure ◽

Calibration Graph ◽

Phase Extraction ◽

Relative Standard

A new solid phase extraction procedure was developed for preconcentration of iron(II) using silica gel-polyethylene glycol (silica-PEG) as an adsorbent. The method is based on retention of iron(II) as 2,2′ bipyridine complex on silica-PEG. The retained complex is eluted by 1.0 mol L−1of sulfuric acid-acetone mixture (1:2) and its absorbance is measured at 518 nm, spectrophotometrically. The effects of different parameters such as pH, concentration of the reagent, eluting reagent, sample volume, amount of adsorbent, and interfering ions were investigated. The calibration graph was linear in the range of 1–60 ng mL−1of iron(II). The limit of detection based on3Sbwas 0.57 ng mL−1and relative standard deviations (R.S.D) for ten replicate measurements of 12 and 42 ng mL−1of iron(II) were 2.4 and 1.7%, respectively. The method was applied to the determination of of iron(II) in water, multivitamin tablet, and spinach samples.

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Presence of zearalenone in the most commonly grown wheat cultivars in Serbia

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn1324101j ◽

2013 ◽

pp. 101-109 ◽

Cited By ~ 1

Author(s):

Igor Jajic ◽

Sasa Krstovic ◽

Biljana Perisic ◽

Sandra Jaksic ◽

Vojislava Bursic ◽

...

Keyword(s):

Liquid Chromatography ◽

Solid Phase Extraction ◽

Limit Of Detection ◽

Solid Phase ◽

Phase Extraction ◽

Wheat Cultivars ◽

Limit Of Quantification ◽

Average Value ◽

Contamination Levels ◽

Maximum Limit

A total of 45 samples of wheat from three different locations in Vojvodina were analyzed for the presence of zearalenone. Analytical methods based on clean-up by solid-phase extraction (SPE) columns and detection by liquid chromatography were used after validation. Limit of detection for ZEA in wheat was 18.6 ?g/kg and the limit of quantification was 56.5 ?g/kg. Recovery values ranged between 86% and 97%. The occurrence of ZEA in wheat was rather high with 53.3% of positive samples with the average value of 330 ?g/kg. Incidences were found from 68 ?g/kg to 1079 ?g/kg. Contamination levels were above the established maximum limit for unprocessed cereals, other than maize, in as many as seventeen samples. These results were compared to the results of investigation of deoxynivalenol and fumonisin content, established in our previous work on the same samples. The results obtained were also compared to those of the neighboring countries where the relevant data existed and to the data of previous studies in our country.

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Application of micro-nanostructured magnetite in separating tetrabromobisphenol A and hexabromocyclododecane from environmental water by magnetic solid phase extraction

PLoS ONE ◽

10.1371/journal.pone.0251021 ◽

2021 ◽

Vol 16 (5) ◽

pp. e0251021

Author(s):

Xiaoping Wang ◽

Fengzhi He ◽

Limin Zhang ◽

Ang Yu

Keyword(s):

Solid Phase Extraction ◽

Limit Of Detection ◽

Solid Phase ◽

Magnetic Solid Phase Extraction ◽

Environmental Water ◽

Mass Spectrometry Analysis ◽

Tetrabromobisphenol A ◽

Phase Extraction ◽

Relative Standard ◽

Magnetic Solid

Two typical brominated flame retardants (BFRs), namely, tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD), were persistent organic pollutants widely detected in various environmental media. This study aimed to successfully synthesize micro-nano-structured magnetite particles (MNMPs) with surface modification by citric acid molecules. The synthesized composites served as an adsorbent for extracting TBBPA and HBCD from environmental water samples followed by gas chromatography–mass spectrometry analysis. The obtained MNMPs were characterized in terms of crystal structure, morphology, size distribution, hydrophobic and hydrophilic performance and magnetism. The results indicated that the MNMPs exhibited high surface area, good dispersibility, and strong magnetic responsiveness for separation. The parameters affecting the extraction efficiency were optimized, including sample pH, amount of sorbents, extraction time and desorption conditions. Under the optimum conditions, the recovery was 83.5 and 107.1%, limit of detection was 0.13 and 0.35μg/mL (S/N = 3), and limit of quantification was 0.37 and 0.59 μg/mL (S/N = 10) for TBBPA and HBCD respectively. The relative standard deviations obtained using the proposed method were less than 8.7%, indicating that the MNMP magnetic solid-phase extraction method had advantages of simplicity, good sensitivity and high efficiency for the extraction of the two BFRs from environmental water.

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Preparation of Polyphenol-Coated CoFe2O3 Nanoparticles for Magnetic Solid-Phase Extraction and Preconcentration of Lawsone by High-Performance Liquid Chromatography – DAD

10.20944/preprints202009.0668.v1 ◽

2020 ◽

Author(s):

Hassan Arkaban ◽

Mohammad Mirzaei ◽

Mansoreh Behzadi

Keyword(s):

Solid Phase Extraction ◽

Limit Of Detection ◽

Solid Phase ◽

Oxidative Polymerization ◽

Magnetic Solid Phase Extraction ◽

Polymerization Process ◽

Phase Extraction ◽

Extraction Temperature ◽

Relative Standard ◽

Magnetic Solid

A novel polyphenol‑coated CoFe2O4 system was synthesized as a magnetic adsorbent by chemical oxidative polymerization process for magnetic solid-phase extraction of lawsone. The synthesized nanoadsorbent showed a spherical morphology with diameters under 50 nm by scanning electron microscopy images. The extraction efficiency of this adsorbent was studied towards the extraction of lawsone from saline aqueous solution in dispersion mode. Major parameters including the type and volume of desorption solvent, amount of sorbent, desorption time, extraction time, extraction temperature, ionic strength and pH were optimized. Under the optimum conditions the relative standard deviation in 0.005 µg mL-1 (inter-day n = 6; intra-day: n = 6; and adsorbent to adsorbent n = 4) were obtained as 5.2, 8.07 and 11.7%, respectively. A linear calibration curve in the range of 0.003–0.5 µg mL-1 with R2 = 0.993 was obtained. The limit of detection and limit of quantification of the method were 0.001 µg mL-1 and 0.003 µg mL-1, respectively. The relative recovery percentages were in range of 90-96.4% for henna leaves, henna shampoo, and henna dermal lotion real samples.

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Determination of Tylosin in Feeds by Liquid Chromatography with Solid-Phase Extraction

Journal of AOAC International ◽

10.1093/jaoac/87.2.341 ◽

2004 ◽

Vol 87 (2) ◽

pp. 341-345 ◽

Cited By ~ 2

Author(s):

Matthew J Gramse ◽

Paul E Jacobson ◽

James C Selkirk

Keyword(s):

Liquid Chromatography ◽

Solid Phase Extraction ◽

Solid Phase ◽

Reversed Phase ◽

Phase Extraction ◽

Column Temperature ◽

Solid Phase Extraction Cartridge ◽

Relative Standard ◽

Phase Liquid

Abstract A method was developed for the determination of tylosin in feeds. The method involves extraction of tylosin with methanol, concentration under a stream of nitrogen, and cleanup using Phenomenex C18 solid-phase extraction cartridge. Analyte separation and quantitation were achieved by gradient reversed-phase liquid chromatography and UV absorbance at 285 nm with a reference wavelength of 320 nm with column temperature of 45°C. Average spike recoveries for samples prepared at 4 spiking levels (22.7, 181, 907, and 1000 g/ton) were 111.0, 94.9, 96.2, and 98.6%, respectively. The overall method precision at each of the 4 spiking levels was ≤ 7.85% relative standard deviation. The limits of detection and quantitation (g/ton) were 2.16 and 7.20 g/ton, respectively.

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