Last data update: Apr 18, 2025. (Total: 49119 publications since 2009)
Records 1-12 (of 12 Records) |
Query Trace: B'Hymer C[original query] |
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Urushiol compounds detected in Toxicodendron-labeled consumer products using mass spectrometry
Zhang AJ , Aschenbeck KA , Law BF , B'Hymer C , Siegel PD , Hylwa SA . Dermatitis 2020 31 (2) 134-139 BACKGROUND: Urushiol, the culprit allergen in Toxicodendron plants such as poison ivy, is an oily mixture of 15 and 17 carbon side chain alk-(en)-yl catechols. Recently, consumer products have been identified that contain Toxicodendron as an ingredient on their label; however, no studies have assessed whether urushiol is indeed present within these products. OBJECTIVE: The aim of the study was to determine whether urushiol compounds are present in consumer products labeled as containing Toxicodendron species. METHODS: Gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry were performed on 9 consumer products labeled as containing Toxicodendron species, including topical homeopathic remedies. Single ion monitoring gas chromatography-mass spectrometry was programmed in selective ion mode to detect 3-methylcatechol characteristic fragment ions of alk-(en)-yl catechols after silanization. Similarly, single ion monitoring liquid chromatography-tandem mass spectrometry was programmed to detect 4 urushiol pentadecylcatechols and 5 urushiol heptadecylcatechols using previously reported mass-to-charge ratios. RESULTS: Gas chromatography-mass spectrometry detected alk-(en)-yl catechols in 67% (6/9) of the products tested. Liquid chromatography-tandem mass spectrometry detected multiple urushiol pentadecylcatechols and heptadecylcatechols in 44% (4/9) of the products tested. CONCLUSIONS: Alk-(en)-yl catechols and multiple urushiols were detected in consumer products listing Toxicodendron species as an ingredient. Clinicians should be aware of these known allergenic ingredients in consumer products. |
A brief overview of HPLC-MS analysis of alkyl methylphosphonic acid degradation products of nerve agents
B'Hymer C . J Chromatogr Sci 2019 57 (7) 606-617 The analysis of degradation products from the classic chemical warfare nerve agents by high-performance liquid chromatography-mass spectrometry has been of much interest in recent years owing to the possible use as a terrorist weapon, and the incidents of chemical weapon usage in recent years in war torn countries. The alkyl methylphosphonic acid degradation products are of a particular interest, and they represent a specific chromatographic technical challenge for use in typical separation systems. Various published methods are summarized in this review and some of the problems associated with the analysis of these compounds are discussed. Future trends of the analysis in this area of research are also considered. |
A review of high performance liquid chromatographic-mass spectrometric urinary methods for anticancer drug exposure of health care workers
Mathias PI , Connor TH , B'Hymer C . J Chromatogr B Analyt Technol Biomed Life Sci 2017 1060 316-324 This review describes published high performance liquid chromatography/mass spectrometry (HPLC-MS) methods for the determination of anticancer drugs in human urine as non-invasive tool for monitoring of health care worker exposure to antineoplastic and cytotoxic drugs. HPLC-MS is a sensitive and specific method for analysis of anticancer drugs and their metabolites in biological fluids. In this review, a tabular summary and overview of published HPLC-MS methods are presented, as well as future trends and limitations in this area of research. |
Mercapturic acids: recent advances in their determination by liquid chromatography/mass spectrometry and their use in toxicant metabolism studies and in occupational and environmental exposure studies
Mathias PI , B'Hymer C . Biomarkers 2016 21 (4) 1-23 This review describes recent selected HPLC/MS methods for the determination of urinary mercapturates that are useful as noninvasive biomarkers in characterizing human exposure to electrophilic industrial chemicals in occupational and environmental studies. High-performance liquid chromatography/mass spectrometry is a sensitive and specific method for analysis of small molecules found in biological fluids. In this review, recent selected mercapturate quantification methods are summarized and specific cases are presented. The biological formation of mercapturates is introduced and their use as indicators of metabolic processing of reactive toxicants is discussed, as well as future trends and limitations in this area of research. |
Validation of an HPLC-MS/MS and wipe procedure for mitomycin C contamination
B'Hymer C , Connor T , Stinson D , Pretty J . J Chromatogr Sci 2014 53 (4) 619-24 A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of mitomycin C, an anticancer drug, from contamination on various surfaces. Mitomycin C is often used in various forms of intraperitoneal chemotherapy, and operating room healthcare worker exposure to this drug is possible. The surface testing method consisted of a wiping procedure utilizing a solution of 20/45/35 (v/v/v) of acetonitrile-isopropanol-water made 0.01 M in ammonium citrate (apparent pH 7.0). The wipe solutions were analyzed by means of HPLC-MS/MS using a reversed-phase gradient system and electrospray ionization in positive ion mode with a triple-quadrupole MS detector. Accuracy and precision of this method were demonstrated by a series of recovery studies of both spiked solutions and extracted wipes from various surfaces (stainless steel, vinyl and Formica(R)) spiked with known levels of mitomycin C. Recoveries of spiked solutions containing the analyte demonstrate mean recoveries (accuracy) ranged from 93 to 105%. Precision as measured by the relative standard deviation (% RSD) of multiple samples (n= 10) at each concentration level demonstrated values of 7.5% or less. The recoveries from spiked surfaces varied from 30 to 99%. The limit of detection for this methodology is approximately 2 ng/100 cm2 equivalent surface area, and the limit of quantitation is approximately 6 ng/100 cm2. |
A survey of liquid chromatographic-mass spectrometric analysis of mercapturic acid biomarkers in occupational and environmental exposure monitoring
Mathias PI , B'Hymer C . J Chromatogr B Analyt Technol Biomed Life Sci 2014 964 136-45 High-performance liquid chromatography/mass spectrometry (HPLC/MS) is sensitive and specific for targeted quantitative analysis and is readily utilized for small molecules from biological matrices. This brief review describes recent selected HPLC/MS methods for the determination of urinary mercapturic acids (mercapturates) which are useful as biomarkers in characterizing human exposure to electrophilic industrial chemicals in occupational and environmental studies. Electrophilic compounds owing to their reactivity are used in chemical and industrial processes. They are present in industrial emissions, are combustion products of fossil fuels, and are components in tobacco smoke. Their presence in both the industrial and general environments are of concern for human and environmental health. Urinary mercapturates which are the products of metabolic detoxification of reactive chemicals provide a non-invasive tool to investigate human exposure to electrophilic toxicants. Selected recent mercapturate quantification methods are summarized and specific cases are presented. The biological formation of mercapturates is introduced and their use as biomarkers of metabolic processing of electrophilic compounds is discussed. Also, the use of liquid chromatography/tandem mass spectrometry in simultaneous determinations of the mercapturates of multiple parent compounds in a single determination is considered, as well as future trends and limitations in this area of research. |
Evaluation and comparison of urinary metabolic biomarkers of exposure for the jet fuel JP-8
B'Hymer C , Krieg E Jr , Cheever KL , Toennis CA , Clark JC , Kesner JS , Gibson R , Butler MA . J Toxicol Environ Health A 2012 75 (11) 661-72 A study of workers exposed to jet fuel propellant 8 (JP-8) was conducted at U.S. Air Force bases and included the evaluation of three biomarkers of exposure: S-benzylmercapturic acid (BMA), S-phenylmercapturic acid (PMA), and (2-methoxyethoxy)acetic acid (MEAA). Postshift urine specimens were collected from various personnel categorized as high (n = 98), moderate (n = 38) and low (n = 61) JP-8 exposure based on work activities. BMA and PMA urinary levels were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and MEAA urinary levels were determined by gas chromatography-mass spectrometry (GC-MS). The numbers of samples determined as positive for the presence of the BMA biomarker (above the test method's limit of detection [LOD = 0.5 ng/ml]) were 96 (98.0%), 37 (97.4%), and 58 (95.1%) for the high, moderate, and low (control) exposure workgroup categories, respectively. The numbers of samples determined as positive for the presence of the PMA biomarker (LOD = 0.5 ng/ml) were 33 (33.7%), 9 (23.7%), and 12 (19.7%) for the high, moderate, and low exposure categories. The numbers of samples determined as positive for the presence of the MEAA biomarker (LOD = 0.1 mcg/ml) were 92 (93.4%), 13 (34.2%), and 2 (3.3%) for the high, moderate, and low exposure categories. Statistical analysis of the mean levels of the analytes demonstrated MEAA to be the most accurate or appropriate biomarker for JP-8 exposure using urinary concentrations either adjusted or not adjusted for creatinine; mean levels of BMA and PMA were not statistically significant between workgroup categories after adjusting for creatinine. |
Detection of DNA damage in workers exposed to JP-8 jet fuel
Krieg Jr EF , Mathias PI , Toennis CA , Clark JC , Marlow KL , B'Hymer C , Singh NP , Gibson RL , Butler MA . Mutat Res 2012 747 (2) 218-27 The genotoxicity of jet propulsion fuel 8 (JP-8) was assessed in the leukocytes of archived blood specimens from U.S. Air Force personnel using the comet assay. No differences in mean comet assay measurements were found between low, moderate, and high exposure groups before or after a 4hour work shift. Before the work shift, mean tail DNA and mean tail (Olive) moment increased as the concentration of benzene measured in end-exhaled breath increased, indicating that prior environmental or work-related exposures to benzene produced DNA damage. The number of cells with highly damaged DNA decreased as the pre-shift benzene concentration in breath increased. It is not clear why the decrease is occurring. Mean tail DNA and mean tail (Olive) moment decreased as the concentrations of benzene and naphthalene measured in breath immediately after the work shift increased. These inverse relationships may reflect a slower rate of absorption or a faster rate of expiration of benzene in the lung. The number of cells with highly damaged DNA increased as the concentration of urinary (2-methoxyethoxy)acetic acid (MEAA) increased. This relationship was not seen in urinary MEAA adjusted for creatinine. MEAA is a metabolite of the deicing agent 2-(2-methoxyethoxy)ethanol contained in JP-8. MEAA or a component of JP-8 correlated with MEAA may have a toxic effect on DNA. |
Comparison and evaluation of urinary biomarkers for occupational exposure to spray adhesives containing 1- bromopropane
Mathias PI , Cheever KL , Hanley KW , Marlow KL , Johnson BC , B'Hymer C . Toxicol Mech Methods 2012 22 (7) 526-32 Three metabolites of 1-bromopropane (1-BP) were measured in urine samples collected from 30 workers exposed to 1-BP at two facilities making furniture seat cushions and evaluated for use as biomarkers of exposure. The mercapturic acid metabolite,N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys), 3-bromopropionic acid (3-BPA), and bromide ion levels (Br(-)) were quantitated for this evaluation. The high exposure group consisted of 13 workers employed as adhesive sprayers who assembled foam cushions using 1-BP containing spray adhesives and the low exposure group consisted of 17 non-sprayers, who worked in various jobs without spraying adhesives. All workers' urine voids were collected over the same 48 hour period at work, and at home before bedtime, and upon awakening. Urinary AcPrCys and Br(-)levels were elevated in the sprayers compared to that ofnon-sprayers. Following HPLC-MS/MS analysis of mercapturic acid metabolite levels, 50 urine samples having the highest levels of AcPrCys were analyzed for 3-BPA. No 3-BPA was detected in any of the samples. The data collected from this study demonstrate that ACPrCys and Br(-) are effective biomarkers of 1-BP exposure, but 3-BPA is not. |
Validation of an HPLC-MS-MS method for the determination of urinary S-benzylmercapturic acid and S-phenylmercapturic acid
B'Hymer C . J Chromatogr Sci 2011 49 (7) 547-53 A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS-MS) method is presented and evaluated for the determination of S-benzylmercapturic acid (S-BMA) and S-phenylmercapturic acid (S-PMA) in human urine. Both of these compounds are important for occupational health owing to their use as biomarkers of exposure to toluene and benzene, respectively. Toluene is used extensively as a solvent, and the health hazards of benzene have been well established. The optimized urine sample preparation scheme consists of solid-phase extraction (SPE) followed by an acetone wash. The chromatographic analysis consists of a reversed-phase gradient system, which uses electrospray ionization in negative-ion mode with a triple-quadrupole mass spectrometric detector. Accuracy and precision of this method are demonstrated by a series of recovery studies of spiked human urine and synthetic urine substitute. Spike levels at 1, 2, 6, 8, and 30 ng/mL for both analytes demonstrate average recoveries (accuracy) ranging from 99 to 110%. Precision as measured by the relative standard deviation (%RSD) of multiple samples (n = 9) at each concentration level was 5.3% or less for both analytes in urine. The limit of detection (LOD) is approximately 0.2 ng/mL for S-BMA and S-PMA. This data, other figures of merit and other factors, such as ion suppression of the electrospray ionization source, are discussed. |
(2-Methoxyethoxy)acetic acid: a urinary biomarker of exposure for jet fuel JP-8
B'Hymer C , Mathias P , Krieg E Jr , Cheever KL , Toennis CA , Clark JC , Kesner JS , Gibson RL , Butler MA . Int Arch Occup Environ Health 2011 85 (4) 413-20 PURPOSE: To demonstrate the utility of the urinary metabolite (2-methoxyethoxy)acetic acid (MEAA) as a biomarker of exposure. 2-(2-methoxyethoxy)ethanol [diethylene glycol monomethyl ether] is an anti-icing agent used in the formulation of JP-8, and it is added at a known uniform 0.1% (v/v) concentration to each batch lot. JP-8 is a kerosene-based fuel containing different compounds that vary in the content of every batch/lot of fuel; thus, MEAA has the potential to be a more specific and a consistent quantitative biomarker for JP-8 exposure. METHODS: MEAA was used to measure exposure of jet propulsion fuel 8 (JP-8) in United States Air Force (USAF) personnel working at six airbases within the United States. Post-shift urine specimens from various personnel including high (n = 98), moderate (n = 38), and low (n = 61) exposure workgroup categories were collected and analyzed by a gas chromatographic-mass spectrometric test method. The three exposure groups were evaluated for the number per group positive for MEAA, and a statistical analysis consisted of pair-wise t-tests for unequal variances was used to test for the differences in mean MEAA concentrations between the exposure groups. RESULTS: The number of samples detected as positive for MEAA exposure, that is, those above the test method's limit of detection (LOD = 0.1 mcg/ml), were 92 (93.9%), 13 (34.2%), and 2 (3.3%) for the high, moderate, and low exposure workgroup categories, respectively. The mean urinary MEAA level was significantly greater in the high exposure category (6.8 mcg/ml), compared to the moderate (0.42 mcg/ml) and the low (0.07 mcg/ml) exposure categories. The maximum concentration of urinary MEAA was 110 mcg/ml for the high exposure category, while 4.8 mcg/ml and 0.2 mcg/ml maximum levels were found in the moderate and low exposure categories, respectively. CONCLUSION: This study demonstrated that urinary MEAA can be used as an accurate biomarker of exposure for JP-8 workers and clearly distinguished the differences in JP-8 exposure by workgroup category. |
Evaluation of a procedure for the simultaneous quantification of 4-ketocyclophosphamide, cyclophosphamide, and ifosfamide in human urine
B'Hymer C , Cheever KL . J Chromatogr Sci 2010 48 (5) 328-333 An accurate and precise analysis procedure is presented for the detection and quantification of cyclophosphamide (CP), 4-ketocyclophosphamide (4-keto-CP), a primary metabolite of CP, and ifosfamide (IF) in human urine. CP and IF are common antineoplastic drugs used for the treatment of many types of cancer. Workers in the healthcare field, including nurses and pharmacists who interact with or prepare prescriptions for patients, have potential low-level exposure to the parent drugs; therefore, an analysis procedure is needed. The main focus of this procedure is the quantitation of 4-keto-CP because it is a primary metabolite of CP exposure and stable under physiological conditions. Sample preparation consists of liquid-liquid extraction of urine with ethyl acetate, and the analysis consists of reversed-phase high-performance liquid chromatography coupled with tandem mass spectrometry for detection of the analytes. Accuracy and precision of this procedure is demonstrated by means of recovery experiments. Recoveries are between 97-105% of theory for the three target analytes at various concentrations (25, 50, 100, and 375 ng/mL for 4-keto-CP; 1, 2, 4, and 15 ng/mL for CP and IF) with relative standard deviations of 8.4% or less. The limit of detection for this procedure is 1 ng/mL for 4-keto-CP, 0.1 ng/mL for CP, and 0.05 ng/mL for IF in urine. |
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