Renata Raina - Academia.edu (original) (raw)

Papers by Renata Raina

Journal of AOAC INTERNATIONAL, 2015

Pesticide residue methods have been developed for a wide variety of food products including cerea... more Pesticide residue methods have been developed for a wide variety of food products including cereal-based foods, nutraceuticals and related plant products, and baby foods. These cereal, fruit, vegetable, and plant-based products provide the basis for many processed consumer products. For cereal and nutraceuticals, which are dry sample products, a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method has been used with additional steps to allow wetting of the dry sample matrix and subsequent cleanup using dispersive or cartridge format SPE to reduce matrix effects. More processed foods may have lower pesticide concentrations but higher co-extracts that can lead to signal suppression or enhancement with MS detection. For complex matrixes, GC/MS/MS or LC/electrospray ionization (positive or negative ion)-MS/MS is more frequently used. The extraction and cleanup methods vary with different sample types particularly for cereal-based products, and these different appro...

Journal of AOAC INTERNATIONAL, 2014

This article reviews the chromatography/MS methodologies for analysis of pesticide residues of or... more This article reviews the chromatography/MS methodologies for analysis of pesticide residues of orphan and difficult chemical classes in a variety of sample matrixes including water, urine, blood, and food. The review focuses on pesticide classes that are not commonly included in multiresidue analysis methods such as highly polar or ionic herbicides including glyphosate, glufosinate, quaternary ammonium, and phenoxy acid herbicides, and some of their major degradation or metabolite products. In addition, dithiocarbamate and phthalimide fungicides, which are thermally unstable and have stability issues in some solvents or sample matrixes, are also examined due to their special needs in residue analysis.

Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in sel... more Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (tri-allate, trifl uralin, ethalfl uralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determina-tion of pesticides in air sample extracts at concentrations 100 pg µL−1 (100 pg m−3 in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5–10 pg µL−1) along with best confi rmation (25 % RSD of ion ratio), while GC-NCI/SRM is recommended for use where added...

Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in sel... more Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (triallate, trifluralin, ethalfluralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determination of pesticides in air sample extracts at concentrations �100 pg μL −1 (�100 pg m −3 in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5–10 pg μL −1) along with best confirmation (�25 % RSD of ion ratio), while GC-NCI/SRM is recommended for use where adde...

This chapter focuses on sample preparation procedures for pesticide analysis of food commodities,... more This chapter focuses on sample preparation procedures for pesticide analysis of food commodities, biological and environmental matrices. This will include pesticides with a broad range of polarity including those that are more amenable to gas chromatographymass spectrometry (organochlorines, organophosphorus pesticides, and pyrethroids) and those commonly analyzed by liquid chromatography-mass spectrometry (carbamates, azole, and strobilurin fungicides, and phenylureas as well as organophosphorus pesticides). QuEChERS (quick, easy, cheap, effective, rugged, and safe) methods or QuEChERS methods with modifications to allow wetting of the dry sample matrix, buffering, changing extraction solvent from acetonitrile to ethyl acetate are examined. Subsequent cleanup using dispersive solid phase extraction or cartridge format solid phase extraction has also been completed to reduce matrix effects. Other solid matrices are frequently extracted with pressurized liquid extraction, microwave a...

Mass Spectrometry, Jun 7, 2017

This chapter reviews the selection of chromatography-mass spectrometry methods for the analysis o... more This chapter reviews the selection of chromatography-mass spectrometry methods for the analysis of organophosphorus pesticides, pyrethroid insecticides, carbamates, and phenylureas. Options with different GC-MS, GC-MS/MS, and LC-MS/MS methods will be discussed for inclusion of the targeted pesticides. In addition, methods for the analysis of metabolites of these chemical classes of pesticides are investigated, including the feasibility of simultaneous analysis with parent pesticides. In some cases, a targeted approach is required for the analyses of metabolites. These methods apply to a wide variety of sample matrices including environmental (air, water, and soil), food (fruits, vegetation, or food products), and biological samples (urine and blood). The focus of the chapter is on MS detection approaches with consideration of the chromatographic separation conditions as required. A short discussion of multiresidue analysis methods and/or where feasible, other chemical classes or selected pesticides from these chemical classes can be analyzed in existing methods is included.

Analytical Chemistry Insights, 2008

A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion ... more A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (triallate, trifluralin, ethalfluralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determination of pesticides in air sample extracts at concentrations <100 pg µL-1 (< 100 pg m-3 in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5-10 pg µL-1) along with best confirmation (<25% RSD of ion ratio), while GC-NCI/SRM is recommended for use where added se...

ACS Symposium Series, 2013

Pesticides - Strategies for Pesticides Analysis, 2011

Molecules, 2020

A liquid chromatography-negative ion electrospray ionization-tandem mass spectrometry method was ... more A liquid chromatography-negative ion electrospray ionization-tandem mass spectrometry method was developed for the simultaneous analysis of bisphenol A, 4-octylphenol, 4-nonylphenol, diethylstilbestrol, 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, prednisone, and prednisolone. This method used solid-phase extraction with an elution solvent of acetonitrile to improve the stability of the analytes. To maintain the stability of analytes analyses were completed within five days. The recoveries ranged from 84 to 112% and the relative standard deviation of analysis of duplicate samples was <10%. The limits of quantitation were 1–10 ng/L. Surface water and wastewater were obtained from five wastewater treatment plants in Saskatchewan. Matrix effects were moderate to severe. Using standard addition calibration, all analytes except diethylstilbestrol and 17α-ethinyl estradiol were detected. There was a low frequency of detection of the target analytes in upstream and downstream ...

Toxics

The extraction of powdered nutraceuticals is challenging due to the low water content and high co... more The extraction of powdered nutraceuticals is challenging due to the low water content and high concentration of matrix components that can lead to significant matrix effects in liquid chromatography-positive ion electrospray ionization-tandem mass spectrometry (LC-ESI+-MS/MS). In this study we assess the feasibility of using pressurized solvent extraction with ethyl acetate to reduce the co-extraction of polar matrix components. Pigment attributed to chlorophyll was removed with in-cell clean-up utilizing Anasorb 747, Florisil®, and C18. Visible inspection of the extracts showed that pigment was removed from matcha, a powdered green tea sample. Pressurized solvent extraction with in-cell clean-up can be utilized to remove pigments from powdered samples such as nutraceuticals. Average matrix effect of the 32 target analytes that observed mass spectrometric signal suppression or soft MS signal enhancement was −41 ± 19% with the majority of analytes having a protonated molecular ion wi...

Air, Soil and Water Research

Two N-trihalomethylthio fungicides were detected in the atmosphere in the Lower Fraser Valley agr... more Two N-trihalomethylthio fungicides were detected in the atmosphere in the Lower Fraser Valley agricultural region of Canada. Captan was detected in both the particle and gas phase with a dominant particle phase fraction observed in both 2005 and 2006 (only total captan atmospheric concentrations were available for 2004). This provides the first evidence of particle transport as a significant atmospheric transport pathway for captan in an agricultural region in Canada. Weekly captan air concentrations reached maximum levels of 13.2 ng m-3 in June 2006, while for folpet total atmospheric levels were lower with maximum reaching 1.7 ng m-3 in August 2004 and generally <1 ng m3 in 2005 and 2006. Folpet is detected in the atmosphere although not previously reported in usage inventories. In the three years examined (2004-2006) captan concentrations observed a seasonal maximum in atmospheric concentrations during spring to early summer coinciding with expected peak usage period on crops ...

American Journal of Analytical Chemistry, 2011

Surface water runoff from urban centers is a major source of environmental pollution which impact... more Surface water runoff from urban centers is a major source of environmental pollution which impacts water quality in downstream aquatic habitats. Phenoxyacid herbicides are some of the most widely globally used herbicides in agriculture and urban environments for weed control. Their transformation products which include chlorophenols can be more toxic than the active ingredients. We used LC/MS/MS to analyzed simultaneously these acid herbicides and their transformation products in stormwater retention ponds taken from an urban environment to examine the occurrence and potential release of these herbicides from urban inputs into downstream waters. 2,4-dichlorophenoxyacetic acid and mecoprop were detected in all samples collected from the ponds and at the highest concentrations, while 2-methyl-4-chlorophenoxyacetic acid was detected only in spring and summer. Two transformation products, 4-chloro-2-methylphenol and 2,4-dichlorophenol were detected in samples primarily at inlet locations on the ponds indicating that degradation had occurred in surface soils prior to surface water runoff.

Air, Soil and Water Research, 2010

Seven solid sorbents including Amberlite ® XAD-2 and XAD-4, Tenax-TA ® , Anasorb-747, Chromosorb ... more Seven solid sorbents including Amberlite ® XAD-2 and XAD-4, Tenax-TA ® , Anasorb-747, Chromosorb 102, 108, and 750 were evaluated for the collection of the gas phase fraction of pesticides under field conditions at an agricultural site, Bratt's Lake, SK, located in the Canadian prairies. The polyurethane foam (PUF)/sorbent cartridge consists of two PUF layers which sandwich the solid sorbent and each layer was analyzed separately to determine which portion of the PUF/solid sorbent retained the pesticides and the extent of breakthrough. The pesticides that had high detection frequency throughout the study and ambient air concentrations well above MDL were triallate, trifluralin, ethalfluralin, and chlorpyrifos. All sorbents had improved collection efficiency as compared to a standard 7.6 cm PUF and the improvement varied with each pesticide. The most effective sorbents for trapping gas phase fraction of pesticides were XAD-2, XAD-4, Tenax-TA, and Chromosorb 108. The only sorbent not recommended for use is Chromosorb 750. For selected sampling periods when ambient concentrations were above detection limits a number of other organochlorine and organophosphorus pesticides also showed more efficient collection with PUF/solid sorbent cartridges as compared to PUF cartridge. Shorter sample collection periods of 4-days improved detection frequency of pesticides.

Analytical chemistry insights, 2008

A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion ... more A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (triallate, trifluralin, ethalfluralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determination of pesticides in air sample extracts at concentrations <100 pg microL(-1) (<100 pg m(-3) in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5-10 pg microL(-1)) along with best confirmation (<25% RSD of ion ratio), while GC-NCI/SRM is recommended for use w...

Journal of Environmental Science and Health, Part B, 2012

Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient of several herbicide products fi... more Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient of several herbicide products first registered for use in 1974 under the tradename Roundup. The use of glyphosate-based herbicides has increased dramatically over the last two decades particularly in association with the adoption of glyphosate-tolerant crops. Glyphosate has been detected in a range of surface waters but this is the first study to monitor its fate in prairie wetlands situated in agricultural fields. An ephemeral wetland (E) and a semi-permanent wetland (SP) were each divided into halves using a polyvinyl curtain. One half of each wetland was fortified with glyphosate with the added mass simulating an accidental direct overspray. Glyphosate dissipated rapidly in the water column of the two prairie wetlands studied (DT 50 values of 1.3 and 4.8 d) which may effectively reduce the impact of exposure of aquatic biota to the herbicide. Degradation of glyphosate to its major metabolite aminomethylphosphonic acid (AMPA) and sorption of the herbicide to bottom sediment were more important pathways for the dissipation of glyphosate from the water column than movement of the herbicide with infiltrating water. Presently, we are not aware of any Canadian guidelines for glyphosate residues in sediment of aquatic ecosystems. Since a substantial portion of glyphosate entering prairie wetlands will become associated with bottom sediments, particularly in ephemeral wetlands, guidelines would need to be developed to assess the protection of organisms that spend all or part of their lifecycle in sediment.

Journal of Environmental Science and Health, Part B, 2008

This paper describes a new analytical method for determination of organophosphorus pesticides (OP... more This paper describes a new analytical method for determination of organophosphorus pesticides (OPs) along with their degradation products involving liquid chromatography (LC) positive ion electrospray (ESI+) tandem mass spectrometry (MS-MS) with selective reaction monitoring (SRM). Chromatography was performed on a Gemini C6-Phenyl (150 mmx2.0 mm, 3 microm) with a gradient elution using water-methanol with 0.1% formic acid, 2 mM ammonium acetate mobile phase at a flow rate of 0.2 mL min(-1). The LC separation and MS/MS operating conditions were optimized with a total analysis time less than 40 minutes. Method detection limits of 0.1-5 microg L(-1) for selected organophosphorus pesticides (OP), OP oxon degradation products, and other degradation products: 3,5,6-trichloro-2-pyridinol (TCP); 2-isopropyl-6-methyl-4-pyrimidol (IMP); and diethyl phosphate (DEP). Some OPs such as fenchlorphos are less sensitive (MDL 30 microg L(-1)). Calibration curves were linear with coefficients of correlation better than 0.995. A three-point identification approach was adopted with area from first selective reaction monitoring (SRM) transition used for quantitative analysis, while a second SRM transition along with the ratio of areas obtained from the first to second transition are used for confirmation with sample tolerance established by the relative standard deviation of the ratio obtained from standards. This new method permitted the first known detection of OP oxon degradation products including chlorpyrifos oxon at Bratt&amp;amp;amp;amp;#39;s Lake, SK and diazinon oxon and malathion oxon at Abbotsford, BC in atmospheric samples. Atmospheric detection limits typically ranged from 0.2-10 pg m(-3).

Journal of Environmental Science and Health, Part B, 2009

Journal of AOAC International, 2012

An LC/MS/MS method has been developed for the determination of azole fungicides in the atmosphere... more An LC/MS/MS method has been developed for the determination of azole fungicides in the atmosphere at low pg/m3 concentrations. Detection limits in the range of 0.16 to 1.2 pg/m3 for a weekly air sample were obtained for the 31 fungicides analyzed. This work represents the first detection of propiconazole, prothioconazole-desthio, and trace levels of hexaconazole in gas phase atmospheric samples collected in a Canadian agricultural region. Samples were collected during April-October 2010 at Bratt&amp;amp;amp;amp;amp;amp;#39;s Lake, Saskatchewan, in the Canadian prairies where there was known historical use of selected azole fungicides. Atmospheric concentrations were above detection limits only during June-August 2010, with maximum concentrations occurring in July at 77.9 and 37.5 pg/m3 for propiconazole and prothioconazole-desthio, respectively. Gas phase atmospheric concentrations of propiconazole and prothioconazole-desthio increased following a spring and early summer with higher than normal daily precipitation. These azole fungicides showed the largest gas phase concentrations during periods of lower temperature and during sampling events with at least 1 day with no precipitation. The higher atmospheric gas phase concentrations of each azole fungicide were observed on different days, indicating different formulations may be in use in the prairie agricultural region.

Environmental Toxicology and Chemistry, 2011

In the present study, an ephemeral (E) and a semipermanent (SP) wetland were divided into halves ... more In the present study, an ephemeral (E) and a semipermanent (SP) wetland were divided into halves using a polyvinyl curtain and one-half of each wetland was treated with dicamba (3,6-dichloro-o-anisic acid), bromoxynil (3,5-dibromo-4-hydroxy-benzonitrile), MCPA [(4-chloro-2-methylphenoxy)acetic acid], 2,4-D [(2,4-dichlorophenoxy)acetic acid], mecoprop-P (R)-2-(4-chloro-otolyloxy)propionic acid], and dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propionic acid] such that concentrations in the water simulated an overspraying event, thus representing a worst-case scenario for wetland contamination. Water and sediment samples were taken over the 77-d study period to monitor herbicide concentrations. The dissipation of all six herbicides could be described by first-order reaction kinetics. In water, the field half-life (DT50) values ranged from 2.3 d (bromoxynil) to 31 d (dichlorprop). All six herbicides were detected in sediment samples from both wetlands. Overall, the phenoxypropionic acids (mecoprop-P and dichlorprop) were more persistent than the phenoxyacetic acids (2,4-D and MCPA) in both sediment and water. Use of bromide ion as a conservative tracer indicated that infiltration through sediment was an important route of water loss in both wetlands, especially in wetland E. Because strong correlations were found between the mass of each herbicide and bromide ion mass in wetland SP (r 2 ¼ 0.59-0.76) and wetland E (r 2 ¼ 0.80-0.95), it is likely that herbicide dissipation was due, in part, to mass lost by way of infiltration through sediment. Environ. Toxicol. Chem.

Journal of AOAC INTERNATIONAL, 2015

Pesticide residue methods have been developed for a wide variety of food products including cerea... more Pesticide residue methods have been developed for a wide variety of food products including cereal-based foods, nutraceuticals and related plant products, and baby foods. These cereal, fruit, vegetable, and plant-based products provide the basis for many processed consumer products. For cereal and nutraceuticals, which are dry sample products, a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method has been used with additional steps to allow wetting of the dry sample matrix and subsequent cleanup using dispersive or cartridge format SPE to reduce matrix effects. More processed foods may have lower pesticide concentrations but higher co-extracts that can lead to signal suppression or enhancement with MS detection. For complex matrixes, GC/MS/MS or LC/electrospray ionization (positive or negative ion)-MS/MS is more frequently used. The extraction and cleanup methods vary with different sample types particularly for cereal-based products, and these different appro...

Journal of AOAC INTERNATIONAL, 2014

This article reviews the chromatography/MS methodologies for analysis of pesticide residues of or... more This article reviews the chromatography/MS methodologies for analysis of pesticide residues of orphan and difficult chemical classes in a variety of sample matrixes including water, urine, blood, and food. The review focuses on pesticide classes that are not commonly included in multiresidue analysis methods such as highly polar or ionic herbicides including glyphosate, glufosinate, quaternary ammonium, and phenoxy acid herbicides, and some of their major degradation or metabolite products. In addition, dithiocarbamate and phthalimide fungicides, which are thermally unstable and have stability issues in some solvents or sample matrixes, are also examined due to their special needs in residue analysis.

Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in sel... more Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (tri-allate, trifl uralin, ethalfl uralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determina-tion of pesticides in air sample extracts at concentrations 100 pg µL−1 (100 pg m−3 in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5–10 pg µL−1) along with best confi rmation (25 % RSD of ion ratio), while GC-NCI/SRM is recommended for use where added...

Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in sel... more Abstract: A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (triallate, trifluralin, ethalfluralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determination of pesticides in air sample extracts at concentrations �100 pg μL −1 (�100 pg m −3 in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5–10 pg μL −1) along with best confirmation (�25 % RSD of ion ratio), while GC-NCI/SRM is recommended for use where adde...

This chapter focuses on sample preparation procedures for pesticide analysis of food commodities,... more This chapter focuses on sample preparation procedures for pesticide analysis of food commodities, biological and environmental matrices. This will include pesticides with a broad range of polarity including those that are more amenable to gas chromatographymass spectrometry (organochlorines, organophosphorus pesticides, and pyrethroids) and those commonly analyzed by liquid chromatography-mass spectrometry (carbamates, azole, and strobilurin fungicides, and phenylureas as well as organophosphorus pesticides). QuEChERS (quick, easy, cheap, effective, rugged, and safe) methods or QuEChERS methods with modifications to allow wetting of the dry sample matrix, buffering, changing extraction solvent from acetonitrile to ethyl acetate are examined. Subsequent cleanup using dispersive solid phase extraction or cartridge format solid phase extraction has also been completed to reduce matrix effects. Other solid matrices are frequently extracted with pressurized liquid extraction, microwave a...

Mass Spectrometry, Jun 7, 2017

This chapter reviews the selection of chromatography-mass spectrometry methods for the analysis o... more This chapter reviews the selection of chromatography-mass spectrometry methods for the analysis of organophosphorus pesticides, pyrethroid insecticides, carbamates, and phenylureas. Options with different GC-MS, GC-MS/MS, and LC-MS/MS methods will be discussed for inclusion of the targeted pesticides. In addition, methods for the analysis of metabolites of these chemical classes of pesticides are investigated, including the feasibility of simultaneous analysis with parent pesticides. In some cases, a targeted approach is required for the analyses of metabolites. These methods apply to a wide variety of sample matrices including environmental (air, water, and soil), food (fruits, vegetation, or food products), and biological samples (urine and blood). The focus of the chapter is on MS detection approaches with consideration of the chromatographic separation conditions as required. A short discussion of multiresidue analysis methods and/or where feasible, other chemical classes or selected pesticides from these chemical classes can be analyzed in existing methods is included.

Analytical Chemistry Insights, 2008

A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion ... more A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (triallate, trifluralin, ethalfluralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determination of pesticides in air sample extracts at concentrations <100 pg µL-1 (< 100 pg m-3 in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5-10 pg µL-1) along with best confirmation (<25% RSD of ion ratio), while GC-NCI/SRM is recommended for use where added se...

ACS Symposium Series, 2013

Pesticides - Strategies for Pesticides Analysis, 2011

Molecules, 2020

A liquid chromatography-negative ion electrospray ionization-tandem mass spectrometry method was ... more A liquid chromatography-negative ion electrospray ionization-tandem mass spectrometry method was developed for the simultaneous analysis of bisphenol A, 4-octylphenol, 4-nonylphenol, diethylstilbestrol, 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, prednisone, and prednisolone. This method used solid-phase extraction with an elution solvent of acetonitrile to improve the stability of the analytes. To maintain the stability of analytes analyses were completed within five days. The recoveries ranged from 84 to 112% and the relative standard deviation of analysis of duplicate samples was <10%. The limits of quantitation were 1–10 ng/L. Surface water and wastewater were obtained from five wastewater treatment plants in Saskatchewan. Matrix effects were moderate to severe. Using standard addition calibration, all analytes except diethylstilbestrol and 17α-ethinyl estradiol were detected. There was a low frequency of detection of the target analytes in upstream and downstream ...

Toxics

The extraction of powdered nutraceuticals is challenging due to the low water content and high co... more The extraction of powdered nutraceuticals is challenging due to the low water content and high concentration of matrix components that can lead to significant matrix effects in liquid chromatography-positive ion electrospray ionization-tandem mass spectrometry (LC-ESI+-MS/MS). In this study we assess the feasibility of using pressurized solvent extraction with ethyl acetate to reduce the co-extraction of polar matrix components. Pigment attributed to chlorophyll was removed with in-cell clean-up utilizing Anasorb 747, Florisil®, and C18. Visible inspection of the extracts showed that pigment was removed from matcha, a powdered green tea sample. Pressurized solvent extraction with in-cell clean-up can be utilized to remove pigments from powdered samples such as nutraceuticals. Average matrix effect of the 32 target analytes that observed mass spectrometric signal suppression or soft MS signal enhancement was −41 ± 19% with the majority of analytes having a protonated molecular ion wi...

Air, Soil and Water Research

Two N-trihalomethylthio fungicides were detected in the atmosphere in the Lower Fraser Valley agr... more Two N-trihalomethylthio fungicides were detected in the atmosphere in the Lower Fraser Valley agricultural region of Canada. Captan was detected in both the particle and gas phase with a dominant particle phase fraction observed in both 2005 and 2006 (only total captan atmospheric concentrations were available for 2004). This provides the first evidence of particle transport as a significant atmospheric transport pathway for captan in an agricultural region in Canada. Weekly captan air concentrations reached maximum levels of 13.2 ng m-3 in June 2006, while for folpet total atmospheric levels were lower with maximum reaching 1.7 ng m-3 in August 2004 and generally <1 ng m3 in 2005 and 2006. Folpet is detected in the atmosphere although not previously reported in usage inventories. In the three years examined (2004-2006) captan concentrations observed a seasonal maximum in atmospheric concentrations during spring to early summer coinciding with expected peak usage period on crops ...

American Journal of Analytical Chemistry, 2011

Surface water runoff from urban centers is a major source of environmental pollution which impact... more Surface water runoff from urban centers is a major source of environmental pollution which impacts water quality in downstream aquatic habitats. Phenoxyacid herbicides are some of the most widely globally used herbicides in agriculture and urban environments for weed control. Their transformation products which include chlorophenols can be more toxic than the active ingredients. We used LC/MS/MS to analyzed simultaneously these acid herbicides and their transformation products in stormwater retention ponds taken from an urban environment to examine the occurrence and potential release of these herbicides from urban inputs into downstream waters. 2,4-dichlorophenoxyacetic acid and mecoprop were detected in all samples collected from the ponds and at the highest concentrations, while 2-methyl-4-chlorophenoxyacetic acid was detected only in spring and summer. Two transformation products, 4-chloro-2-methylphenol and 2,4-dichlorophenol were detected in samples primarily at inlet locations on the ponds indicating that degradation had occurred in surface soils prior to surface water runoff.

Air, Soil and Water Research, 2010

Seven solid sorbents including Amberlite ® XAD-2 and XAD-4, Tenax-TA ® , Anasorb-747, Chromosorb ... more Seven solid sorbents including Amberlite ® XAD-2 and XAD-4, Tenax-TA ® , Anasorb-747, Chromosorb 102, 108, and 750 were evaluated for the collection of the gas phase fraction of pesticides under field conditions at an agricultural site, Bratt's Lake, SK, located in the Canadian prairies. The polyurethane foam (PUF)/sorbent cartridge consists of two PUF layers which sandwich the solid sorbent and each layer was analyzed separately to determine which portion of the PUF/solid sorbent retained the pesticides and the extent of breakthrough. The pesticides that had high detection frequency throughout the study and ambient air concentrations well above MDL were triallate, trifluralin, ethalfluralin, and chlorpyrifos. All sorbents had improved collection efficiency as compared to a standard 7.6 cm PUF and the improvement varied with each pesticide. The most effective sorbents for trapping gas phase fraction of pesticides were XAD-2, XAD-4, Tenax-TA, and Chromosorb 108. The only sorbent not recommended for use is Chromosorb 750. For selected sampling periods when ambient concentrations were above detection limits a number of other organochlorine and organophosphorus pesticides also showed more efficient collection with PUF/solid sorbent cartridges as compared to PUF cartridge. Shorter sample collection periods of 4-days improved detection frequency of pesticides.

Analytical chemistry insights, 2008

A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion ... more A comparison of detection limits of gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) with gas chromatography-tandem mass spectrometry (GC-MS/MS) in selected reaction monitoring (SRM) mode with both electron ionization (EI) and negative-ion chemical ionization (NCI) are presented for over 50 pesticides ranging from organochlorines (OCs), organophosphorus pesticides (OPs) and pre-emergent herbicides used in the Canadian prairies (triallate, trifluralin, ethalfluralin). The developed GC-EI/SIM, GC-NCI/SIM, and GC-NCI/SRM are suitable for the determination of pesticides in air sample extracts at concentrations <100 pg microL(-1) (<100 pg m(-3) in air). No one method could be used to analyze the range of pre-emergent herbicides, OPs, and OCs investigated. In general GC-NCI/SIM provided the lowest method detection limits (MDLs commonly 2.5-10 pg microL(-1)) along with best confirmation (<25% RSD of ion ratio), while GC-NCI/SRM is recommended for use w...

Journal of Environmental Science and Health, Part B, 2012

Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient of several herbicide products fi... more Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient of several herbicide products first registered for use in 1974 under the tradename Roundup. The use of glyphosate-based herbicides has increased dramatically over the last two decades particularly in association with the adoption of glyphosate-tolerant crops. Glyphosate has been detected in a range of surface waters but this is the first study to monitor its fate in prairie wetlands situated in agricultural fields. An ephemeral wetland (E) and a semi-permanent wetland (SP) were each divided into halves using a polyvinyl curtain. One half of each wetland was fortified with glyphosate with the added mass simulating an accidental direct overspray. Glyphosate dissipated rapidly in the water column of the two prairie wetlands studied (DT 50 values of 1.3 and 4.8 d) which may effectively reduce the impact of exposure of aquatic biota to the herbicide. Degradation of glyphosate to its major metabolite aminomethylphosphonic acid (AMPA) and sorption of the herbicide to bottom sediment were more important pathways for the dissipation of glyphosate from the water column than movement of the herbicide with infiltrating water. Presently, we are not aware of any Canadian guidelines for glyphosate residues in sediment of aquatic ecosystems. Since a substantial portion of glyphosate entering prairie wetlands will become associated with bottom sediments, particularly in ephemeral wetlands, guidelines would need to be developed to assess the protection of organisms that spend all or part of their lifecycle in sediment.

Journal of Environmental Science and Health, Part B, 2008

This paper describes a new analytical method for determination of organophosphorus pesticides (OP... more This paper describes a new analytical method for determination of organophosphorus pesticides (OPs) along with their degradation products involving liquid chromatography (LC) positive ion electrospray (ESI+) tandem mass spectrometry (MS-MS) with selective reaction monitoring (SRM). Chromatography was performed on a Gemini C6-Phenyl (150 mmx2.0 mm, 3 microm) with a gradient elution using water-methanol with 0.1% formic acid, 2 mM ammonium acetate mobile phase at a flow rate of 0.2 mL min(-1). The LC separation and MS/MS operating conditions were optimized with a total analysis time less than 40 minutes. Method detection limits of 0.1-5 microg L(-1) for selected organophosphorus pesticides (OP), OP oxon degradation products, and other degradation products: 3,5,6-trichloro-2-pyridinol (TCP); 2-isopropyl-6-methyl-4-pyrimidol (IMP); and diethyl phosphate (DEP). Some OPs such as fenchlorphos are less sensitive (MDL 30 microg L(-1)). Calibration curves were linear with coefficients of correlation better than 0.995. A three-point identification approach was adopted with area from first selective reaction monitoring (SRM) transition used for quantitative analysis, while a second SRM transition along with the ratio of areas obtained from the first to second transition are used for confirmation with sample tolerance established by the relative standard deviation of the ratio obtained from standards. This new method permitted the first known detection of OP oxon degradation products including chlorpyrifos oxon at Bratt&amp;amp;amp;amp;#39;s Lake, SK and diazinon oxon and malathion oxon at Abbotsford, BC in atmospheric samples. Atmospheric detection limits typically ranged from 0.2-10 pg m(-3).

Journal of Environmental Science and Health, Part B, 2009

Journal of AOAC International, 2012

An LC/MS/MS method has been developed for the determination of azole fungicides in the atmosphere... more An LC/MS/MS method has been developed for the determination of azole fungicides in the atmosphere at low pg/m3 concentrations. Detection limits in the range of 0.16 to 1.2 pg/m3 for a weekly air sample were obtained for the 31 fungicides analyzed. This work represents the first detection of propiconazole, prothioconazole-desthio, and trace levels of hexaconazole in gas phase atmospheric samples collected in a Canadian agricultural region. Samples were collected during April-October 2010 at Bratt&amp;amp;amp;amp;amp;amp;#39;s Lake, Saskatchewan, in the Canadian prairies where there was known historical use of selected azole fungicides. Atmospheric concentrations were above detection limits only during June-August 2010, with maximum concentrations occurring in July at 77.9 and 37.5 pg/m3 for propiconazole and prothioconazole-desthio, respectively. Gas phase atmospheric concentrations of propiconazole and prothioconazole-desthio increased following a spring and early summer with higher than normal daily precipitation. These azole fungicides showed the largest gas phase concentrations during periods of lower temperature and during sampling events with at least 1 day with no precipitation. The higher atmospheric gas phase concentrations of each azole fungicide were observed on different days, indicating different formulations may be in use in the prairie agricultural region.

Environmental Toxicology and Chemistry, 2011

In the present study, an ephemeral (E) and a semipermanent (SP) wetland were divided into halves ... more In the present study, an ephemeral (E) and a semipermanent (SP) wetland were divided into halves using a polyvinyl curtain and one-half of each wetland was treated with dicamba (3,6-dichloro-o-anisic acid), bromoxynil (3,5-dibromo-4-hydroxy-benzonitrile), MCPA [(4-chloro-2-methylphenoxy)acetic acid], 2,4-D [(2,4-dichlorophenoxy)acetic acid], mecoprop-P (R)-2-(4-chloro-otolyloxy)propionic acid], and dichlorprop [(RS)-2-(2,4-dichlorophenoxy)propionic acid] such that concentrations in the water simulated an overspraying event, thus representing a worst-case scenario for wetland contamination. Water and sediment samples were taken over the 77-d study period to monitor herbicide concentrations. The dissipation of all six herbicides could be described by first-order reaction kinetics. In water, the field half-life (DT50) values ranged from 2.3 d (bromoxynil) to 31 d (dichlorprop). All six herbicides were detected in sediment samples from both wetlands. Overall, the phenoxypropionic acids (mecoprop-P and dichlorprop) were more persistent than the phenoxyacetic acids (2,4-D and MCPA) in both sediment and water. Use of bromide ion as a conservative tracer indicated that infiltration through sediment was an important route of water loss in both wetlands, especially in wetland E. Because strong correlations were found between the mass of each herbicide and bromide ion mass in wetland SP (r 2 ¼ 0.59-0.76) and wetland E (r 2 ¼ 0.80-0.95), it is likely that herbicide dissipation was due, in part, to mass lost by way of infiltration through sediment. Environ. Toxicol. Chem.