Pentafluorobenzyl Bromide Research Articles

Oxylipin Profiling of the Hypersensitive Response in Arabidopsis thaliana: FORMATION OF A NOVEL OXO-PHYTODIENOIC ACID-CONTAINING GALACTOLIPID, ARABIDOPSIDE E

Oxylipin Profiling of the Hypersensitive Response in Arabidopsis thaliana: FORMATION OF A NOVEL OXO-PHYTODIENOIC ACID-CONTAINING GALACTOLIPID, ARABIDOPSIDE E

Determination and Levels of the Biocide ortho-Phenylphenol in Canned Beers from Different Countries

A method was developed for the determination of the biocide ortho-phenylphenol (biphenyl-2-ol; OPP) in beer, using deuterated OPP as an internal standard. A new liquid-liquid extraction procedure, employing acetonitrile, diethyl ether, and n-pentane, afforded rapid phase separation. The evaporated extract was derivatized with pentafluorobenzyl bromide in a water-acetonitrile mixture that was buffered with potassium carbonate, followed by extraction of the derivative into cyclohexane and analysis by gas chromatography-mass spectrometry in electron ionization mode. The method enables the detection of OPP in 50 mL of beer at concentrations as low as 0.1 microg/L and provides a linear range of quantification of 0.5-40 microg/L. Samples from 61 beers canned over the past 12 years and sold in 27 countries were analyzed for OPP. In 40 of them, the target compound was present at concentrations of 1.2-40 microg/L. Our investigations indicate that the ends of the cans, which contain sealing material presumably treated with OPP, are responsible for this contamination.

HS-SPME Determination of Volatile Carbonyl and Carboxylic Compounds in Different Matrices

Specific chromatographic methodologies are developed for the analysis of carboxylic acids (C(2)-C(6), benzoic) and aldehydes (C(2)-C(10)) of low molecular weight in diverse matrices, such as air, automotive exhaust gases, human breath, and aqueous matrices. For carboxylic acids, the method is based on their reaction with pentafluorobenzyl bromide in aqueous solution, followed by the separation and identification of the resultant pentafluorobenzyl esters by means of headspace (HS)-solid-phase microextraction (SPME) combined with gas chromatography (GC) and electron capture detection (ECD). Detection limits in the microg/m(3) range are reached, with relative standard deviation (RSD) less than 10% and linear response (R(2) > 0.99) over two orders of magnitude. The analytical methodology for aldehydes is based on SPME with simultaneous derivatization of the analytes on the fiber, by reaction with pentafluorophenylhydrazine. The derivatization reagent is previously deposited on the SPME fiber, which is then exposed to the gaseous matrix or the HS of the sample solution. The pentafluorophenyl hydrazones formed on the fiber are analyzed selectively by means of GC-ECD, with detection limits in the ng/m(3) range, RSD less than 10%, and linear response (R(2) > 0.99) over two orders of magnitude.

Trace determination of tamoxifen and 5-fluorouracil in hospital and urban wastewaters

Tamoxifen and 5-fluorouracil are widely used in cancer therapy. They are highly toxic (teratogenic, mutagenic, etc.), as are most of the anticancer drugs. Two methods were set up to analyse these drugs in wastewaters to evaluate the potential for environmental contamination by cytostatic agents. Liquid–liquid extraction followed by purification on OASIS® MCX cartridge and gas chromatography with mass spectrometry detection (GC-MS) was used for the analysis of tamoxifen. 5-Fluorouracil was extracted with an ENV+ (Isolute) cartridge (solid-phase extraction), derivatized with pentafluorobenzyl bromide (PFBBr) and detected by GC-MS. Both methods showed good recoveries (>70%), repeatability (RSD<10%) and limits of detection (LOD 6–15 ng/L). Wastewaters from a residential area, a hospital, and sewage-treatment plants (STPs) were analysed using the analytical methods developed in this study. Tamoxifen was detected in wastewaters of the hospital, residential area, and influent of STPs, but not in treated wastewaters. 5-Fluorouracil in all wastewaters was below the LOD of the analytical method.

Automated analysis of 2-methyl-3-furanthiol and 3-mercaptohexyl acetate at ng L −1 level by headspace solid-phase microextracion with on-fibre derivatisation and gas chromatography–negative chemical ionization mass spectrometric determination

A fast and automated method for the analysis at ng L −1 level of aroma-powerful polyfunctional thiols has been developed and applied to wine. The sample is just poured in a 20 mL vial and its vapour extracted with a poly(dimethylsiloxane)–divinylbenzene (PDMS–DVB) solid-phase microextraction fibre (65 μm thickness) previously exposed to vapours of the reactive (pentafluorobenzyl bromide) and of an alkali (tributylamine). The derivatised compounds are subsequently desorbed in the GC system and determined by negative chemical ionization mass spectrometry. The method is fully automated by using a Combi-Pal autosampler conveniently programmed. The analysis takes 50 min, which contrasts to the long and tedious methods previously proposed. The development of an optimal procedure is constrained by the aggressive character of the reagent (towards the fibre and the chromatographic column), its volatility and the quality of the blanks that can be obtained. Therefore, a critical step was fixing in the fibre a “safe” and repetitive amount of reagent. This was achieved by exposing the fibre (5 min) to the vapours of a water:acetone (9:1) solution containing 200 mg L −1 of reagent. Under these conditions, the extraction-derivatisation of analytes improves with time and temperature, and the best working conditions are dictated by a compromise between sensitivity, speed and chromatographic performance. Although analytes studied were 2-methyl-3-furanthiol, 4-mercapto-4-methyl-2-pentanone, 3-mercaptohexanol, 2-furanmethanethiol and 3-mercaptohexyl acetate, a good analytical performance could be achieved only for these two last compounds. Both of them can be repetitively (10% < RSD < 20%) determined in wine at concentrations below 0.1 ng L −1. Other aspects considered in the method setup were the oxidation of analytes during the process, and the electron-capture detection (ECD) and MS properties of the pentafluorobenzyl derivatives of different polyfunctional thiols.

Effect of Arachidonic Acid Reacylation on Leukotriene Biosynthesis in Human Neutrophils Stimulated with Granulocyte-macrophage Colony-stimulating Factor and Formyl-methionyl-leucyl-phenylalanine

Priming of human neutrophils with granulocyte-macrophage colony-stimulating factor (GM-CSF) followed by treatment with formyl-methionyl-leucyl-phenylalanine (fMLP) stimulates cells in a physiologically relevant manner with modest 5-lipoxygenase activation and formation of leukotrienes. However, pretreatment of neutrophils with thimerosal, an organomercury thiosalicylic acid derivative, led to a dramatic increase (>50-fold) in the production of leukotriene B(4) and 5-hydroxyeicosatetraenoic acid, significantly higher than that observed after stimulation with calcium ionophore A23187. Little or no effect was observed with thimerosal alone or in combination with either GM-CSF or fMLP. Elevation of [Ca(2+)](i) induced by thimerosal in neutrophils stimulated with GM-CSF/fMLP was similar but more sustained compared with samples where thimerosal was absent. However, [Ca(2+)](i) was significantly lower compared with calcium ionophore-treated cells, suggesting that a sustained calcium rise was necessary but not sufficient to explain the effects of this compound on the GM-CSF/fMLP-stimulated neutrophil. Thimerosal was found to directly inhibit neutrophil lysophospholipid:acyl-CoA acyltransferase activity at the doses that stimulate leukotriene production, and analysis of lysates from neutrophil preparations stimulated in the presence of thimerosal showed a marked increase in free arachidonic acid, supporting the inhibition of the reincorporation of this fatty acid into the membrane phospholipids as a mechanism of action for this compound. The dramatic increase in production of leukotrienes by neutrophils when a physiological stimulus such as GM-CSF/fMLP is employed in the presence of thimerosal suggests a critical regulatory role of arachidonate reacylation that limits leukotriene biosynthesis in concert with 5-lipoxygenase and cytosolic phospholipase A(2)alpha activation.

Effects of garlic ingestion in humans on the formation of urinary nitrosoproline

In vitro and animal studies suggest that compounds found in garlic may play a role in mediating the bioactivation of some carcinogens. N-nitrosoproline (NPRO) has been used in feeding studies as a biomarker for the formation of N-alkylnitrosamines. A controlled-feeding study was performed at Penn State University to test the hypothesis that garlic consumption inhibits nitrosamine formation. In this study, subjects (3 to 5 per group) consumed either 0 (control) 1, 3 or 5 grams of fresh garlic, 3 grams Kyolic (a commercial garlic supplement) or 500 mg vitamin C for 1 day following a 3 day run-in period in which 300 mg nitrate and 500 mg proline was consumed daily with a standard meal. Urine was collected during the last 24 hours and analyzed for NPRO. Aliquots were diluted with mobile phase, fractionated by isocratic reversed phase HPLC, and the fraction containing NPRO was dried and derivatized with pentafluorobenzyl bromide (PFB). The NPRO-PFB derivative was isolated using a second, gradient reversed-phase HPLC step and quantified by gas chromatography/ negative chemical ionization mass spectrometry. 13C5NPRO was used as the internal standard. Preliminary analysis of the samples indicates that NPRO excretion was reduced to nearly undetectable levels by treatments with 5 grams garlic, 3 grams Kyolic, and 500 mg vitamin C compared to controls. Analysis of the remaining samples is underway. In conclusion, the consumption of a single dose of prepared garlic, either fresh or as a supplement, reduced the excretion of NPRO under controlled-feeding conditions as much as a vitamin C supplement.

Simultaneous determination of urinary dialkylphosphate metabolites of organophosphorus pesticides using gas chromatography–mass spectrometry

In this study, we developed a safe and sensitive method for the simultaneous determination of urinary dialkylphosphates (DAPs), metabolites of organophosphorus insecticides (OPs), including dimethylphosphate (DMP), diethylphosphate (DEP), dimethylthiophosphate (DMTP), and diethylthiophosphate (DETP), using a pentafluorobenzylbromide (PFBBr) derivatization and gas chromatography-mass spectrometry (GC-MS). Several parameters were investigated: pH on evaporation, reaction temperature and time for the derivatization, the use of an antioxidant for preventing oxidation, and a clean-up step. The pH was set at 6, adjusted with K2CO3, and the reaction temperature and time of derivatization were 80 degrees C and 30 min, respectively. Sodium disulfite was chosen as an antioxidant. The clean-up step was performed with a Florisil/PSE mini-column to remove the unreacted PFBBr and sample matrix. This established procedure markedly shortened the sample preparation time to only about 3 h, and completely inhibited the unwanted oxidization of dialkylthiophosphates. The limits of determination (LOD) were approximately 0.3 microg/L for DMP, and 0.1 microg/L for DEP, DMTP, and DETP in 5 mL of human urine. Within-series and between-day imprecision for the present method using pooled urine spiked with DAPs was less than 20.6% in the calibration range of 1-300 microg/L, and the mean recovery was 56.7-60.5% for DMP, 78.5-82.7% for DEP, 88.3-103.9% for DMTP, and 84.2-92.4% for DETP. This method detected geometric mean values of the urinary DAPs in Japanese with and without occupational exposure to OPs, 16.6 or 27.4 for DMP, 1.0 or 0.7 for DEP, 1.3 or 2.3 for DMTP, and 1.0 or 1.1 microg/L for DETP, respectively. The present method, which does not require special equipment except for GC-MS, is quick, safe, and sensitive enough to be adopted in routine biological monitoring of non-occupational as well as occupational exposure to OPs.

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry

A validated GC-MS method for the analysis of urinary metabolites of alkyl benzenes is reported. Metabolites for exposure to toluene, xylene and ethylbenzene were analyzed simultaneously using stable isotope substituted internal standards. The method entailed acidic deconjugation of urine samples followed by extractive alkylation with pentafluorobenzyl bromide as alkylating agent. The resulting pentafluorobenzyl derivatives of ortho-, meta-, para-cresol, mandelic acid (MA), hippuric acid (HA) and ortho-, meta-, para-methylhippuric acid (MHA) were then quantified by SIM. Optimized reaction conditions for the extractive alkylation step are reported. The derivatives were found to be sufficiently stable for overnight batch analysis. The LODs were below 0.1 micromol/L for the cresols and below 1 micromol/L for MA and the HAs. Within-batch precision for o-MHA was 7%, for m-MHA 5%, for p-MHA 5.2% and below 5% for the rest of the analytes.

Simultaneous determination of thyreostatic residues in animal tissues by matrix solid-phase dispersion and gas chromatography–mass spectrometry

A method for determination of thyreostatic residues in animal tissues by matrix solid-phase dispersion (MSPD) and gas chromatography-mass spectrometry in selected ion detection mode was developed. Thyreostatic compounds in different matrices were extracted and purified by combination of MSPD and subsequent solid-phase extraction. Silica gel was selected as the solid support of both procedures and the conditions of the procedures were optimized. Thyreostats were derivatized with pentafluorobenzylbromide (PFBBr) in strong basic medium and then with N-methyl- N-(trimethylsilyl)-trifluoroacetamide (MSTFA), which can improve the yields of derivatization for thyreostats, the repeatability, and therefore the limits of detection (LOD) of thyreostats. The limits of detection reached 10 μg/kg (2-thiouracil, 6-methyl-2-thiouracil and 6-propyl-2-thiouracil), 20 μg/kg (6-phenyl-2-thiouracil) and 50 μg/kg (tapazole) with high recoveries (more than 70% for most of thyreostats) and relative standard deviations between 4.5% and 8.7%.

Determining15N enrichment of dissolved organic nitrogen in environmental waters by gas chromatography/negative-ion chemical ionization mass spectrometry

To minimize the required sample volume and simplify the overall procedure for determining 15N enrichment of dissolved organic nitrogen (DON) in environmental waters, we employed derivatization of NO3− with pentafluorobenzyl bromide and gas chromatography/negative-ion chemical ionization mass spectrometry (GC-NICI-MS). The pretreatment processes to remove inorganic nitrogen were optimized to ensure recovery of labile DON molecules, and the derivatization procedure for NO2− and NO3− was optimized for environmental samples. The required sample volume is 10 mL or less and the detection limit is about 0.015 µmol 15N L−1, or 0.3 atomic percent excess of 15N for water samples containing 5 µmol DON L−1. This method can also be applied to 15N enrichment analysis of particulate organic nitrogen. We applied the developed method to measure DON production rate by the hermatypic coral Porites cylindrica during incubation with 15N-labeled NO3−.

Measurement of N7-(2‘-Hydroxyethyl)guanine in Human DNA by Gas Chromatography Electron Capture Mass Spectrometry

An improved method is presented, based on gas chromatography-electron capture mass spectrometry (GC-EC-MS), for measuring N7-(2'-hydroxyethyl)guanine (N7-HEG) in DNA from an in vivo sample. The method was used to detect this adduct in amounts of human DNA ranging from 0.07 to 11.5 microg isolated from granulocytes. In this method, the DNA is spiked with a stable isotope internal standard (N7-HEG-d4) and heated in water to release the adduct in a nucleobase form. After the adduct is extracted into 1-butanol, it is purified by reverse phase HPLC and derivatized with HONO, pentafluorobenzyl bromide, and pivalic anhydride. Further purification by silica solid phase extraction and reverse phase HPLC is done prior to injection into a GC-EC-MS. Relatively clean GC-EC-MS chromatograms result, contributing to the high sensitivity that is observed. In the samples tested, from 1.6 to 240 N7-HEG adducts in 10(7) nucleotides were observed, a 150-fold range.

Quantitative determination of fluvastatin in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry using [18O2]‐fluvastatin as an internal standard

A sensitive and specific method for the quantitative determination of fluvastatin in human plasma is presented. The drug was isolated from plasma by extractive alkylation with pentafluorobenzyl bromide and further derivatized to the bis-trimethylsilyl derivative. [18O2]-Fluvastatin was prepared from unlabelled fluvastatin and used as an internal standard. Gas chromatography/mass spectrometry under negative ion chemical ionization conditions was used for quantitative measurement of the drug, using m/z 554.26 and 558.26 for target and internal standard, respectively. Calibration graphs were linear within a range of 2 and 512 ng mL(-1) plasma. Intra-day precision was 0.94% (2 ng mL(-1)), 2.53% (8.2 ng mL(-1)), 2.16% (81.9 ng mL(-1)) and 3.26% (409.6 ng mL(-1)); inter-day variability was found to be 1.64% (2 ng mL(-1)), 0.97% (8.2 ng mL(-1)), 1.97% (81.9 ng mL(-1)) and 2.01% (409.6 ng mL(-1)). Intra-day accuracy showed deviations of 0.6% (2 ng mL(-1)), 0.37% (8.2 ng mL(-1)), -1.52% (81.9 ng mL(-1)) and -1.67% (409.6 ng mL(-1)); inter-day accuracy was of -1.64% (2 ng mL(-1)), -1.13% (8.2 ng mL(-1)), -2.28% (81.9 ng mL(-1)) and -0.46% (409.6 ng mL(-1)). The stable isotope labelled standard was found to be stable under the analytical conditions.

Development and Validation of a Gas Chromatography/Mass Spectrometry Procedure for Confirmation of Para-Toluenesulfonamide in Edible Fish Fillet Tissue

Chloramine-T is a disinfectant being developed as a treatment for bacterial gill disease in cultured fish. As part of the drug approval process, a method is required for the confirmation of chloramine-T residues in edible fish tissue. The marker residue that will be used to determine the depletion of chloramine-T residues from the edible tissue of treated fish is para-toluenesulfonamide (p-TSA), a metabolite of chloramine-T. The development and validation of a procedure for the confirmation of p-TSA is described. Homogenized fish tissue is dried by mixing with anhydrous sodium sulfate, and the mixture is extracted with methylene chloride. The extract is passed through a silica gel solid-phase extraction column, from which p-TSA is subsequently eluted with acetonitrile. The acetonitrile extract is evaporated, and the oily residue is dissolved in hexane. The hexane solution is shaken with fresh acetonitrile. The acetonitrile solution is evaporated and the residue is redissolved in dilute potassium hydroxide solution. The aqueous solution is extracted with methylene chloride to further remove more of the fat co-extractive. The aqueous solution is reacted with pentafluorobenzyl bromide in presence of tetrabutylammonium hydrogensulfate. The resulting di-(pentafluorobenzyl) derivative of p-TSA is analyzed by gas chromatography/mass spectrometry. This method permits the confirmation of p-TSA in edible fish tissue at 20 ppb.

Group 9 complexes of an N-heterocycle carbene bearing a pentafluorobenzyl substituent: attempted dehydrofluorinative coupling of cyclopentadienyl and N-heterocycle carbene ligands

Treatment of N-methylimidazole with pentafluorobenzyl bromide produces 1-pentafluorobenzyl-3-methylimidazolium bromide ( 1), which reacts with silver(I) oxide to give the N-heterocycle carbene (NHC) complex 1-pentafluorobenzyl-3-methylimidazolin-2-ylidene silver(I) bromide ( 2). Complex 2 acts as a carbene transfer reagent giving the complexes [(η 5-C 5Me 5)MCl 2(NHC)] ( 3a, M = Rh; 3b M = Ir) on reaction with [(η 5-C 5Me 5)MCl(μ-Cl)] 2. An attempt to use intramolecular dehydrofluorinative coupling methodology to link the carbene and the pentamethylcyclopentadienyl ligands of [(η 5-C 5Me 5)RhCl(CN t Bu)(NHC)]BF 4 was unsuccessful.

Determination of trans-arachidonic acid isomers in human blood plasma

Endogenous trans fatty acids originate from diet, but recent studies also suggest that cis–trans isomerization of fatty acids is possible by nitrogen dioxide radical, a product of NO and nitrite oxidation. We developed a method for quantitative analysis of four trans-arachidonic acids (TAA) in human plasma using isotopic dilution gas chromatography/mass spectrometry (GC/MS) with deuterium-labeled internal standard. Esterification of the plasma fatty acid extract with pentafluorobenzyl (PFB) bromide followed by high-performance liquid chromatography purification yielded a fairly pure fraction containing TAA-PFB esters that was analyzed by GC/MS. Partial separation of the TAA isomers was obtained on various GC columns. Comparison of the retention time with the synthetic standards revealed that all four TAA isomers are present in human plasma. The mean concentration of TAA in human plasma was 20.2 ng/ml. The levels of isomers were 12.48 ± 1.28, 2.75 ± 0.39, and 4.99 ± 0.74 ng/ml for 5 E-AA + 11 E-AA, 8 E-AA, and 14 E-AA, respectively. The identification of TAA in plasma suggests that isomerization of arachidonic acid occurs in vivo. Our method allows distinguishing between the dietary and the NO 2-dependent mechanisms of trans fatty acid formation and will be useful in defining the role of TAA as an in vivo marker of nitrooxidative stress in clinical and experimental settings.

Rapid preparation of human urine and plasma samples for analysis of F 2-isoprostanes by gas chromatography-mass spectrometry

Reliable MS-based methods have been developed for the measurement of free and esterified F 2-isoprostanes. However, prior to sample analysis several steps of purification, including solid-phase extraction followed by TLC or HPLC, are usually required, making it tedious to analyze large sample numbers, e.g., for population studies. We report a quick sample purification method using anion exchange solid phase extraction (SPE), which is highly selective for acidic compounds. Urine and hydrolyzed plasma of healthy individuals were acidified before SPE extraction, washed with 4 different solvent mixtures and finally eluted with ethyl acetate. The eluted samples were first derivatized with pentafluorobenzyl bromide followed by a second derivatization with bis-(trimethylsilyl)trifluoroacetamide. F 2-isoprostanes were analyzed by GC-MS-NCI. The method was highly sensitive; the limit of detection at 5:1 signal-to-noise ratio was 0.037 ng/ml and 0.007 ng/mg creatinine for plasma and urine, respectively. Anion exchange SPE extraction for F 2-isoprostane showed recovery of 55–65% and high linearity for concentration 0–1.0 ng/ml for urine (CV=4.08%, r 2=0.990) and 0–0.5 ng/ml for plasma (CV=4.07%, r 2=0.998). Fasting for 6 h significantly increased plasma F 2-isoprostanes levels, which has implications for the design of intervention studies using this biomarker.

Simultaneous determination of formate and acetate in whole blood and urine from humans using gas chromatography–mass spectrometry

We devised a sensitive and simple method for simultaneous determination of formate and acetate in whole blood and urine from humans using gas chromatography–mass spectrometry. Formate and acetate were alkylated with pentafluorobenzyl bromide in the mixture of acetone and phosphate buffer (pH 6.8). The derivatives obtained were analyzed using gas chromatography–mass spectrometry in positive-ion electron ionization (EI) mode. The lower limit of detection for both compounds was 0.02 mM. The calibration curves for formate and acetate were linear over the concentration range from 0.05 to 5.0 mM. Accuracy and precision of the method were evaluated and the coefficients of variation were within 10%. With use of this method, levels of formate and acetate in whole blood can be determined in forensic cases.

Measurement of nitric oxide synthase activity in vivo and in vitro by gas chromatography-mass spectrometry.

Measurement of the nitric oxide (NO) metabolites nitrite and nitrate in biological matrices is a reliable method to assess NO synthase (NOS) activity. Unlike the "L-citrulline assay," the "nitrite/nitrate assay" is generally applicable and permits acquisition of maximum information about what NOS did actually produce. From the various analytical approaches and methods available so far for the quantitation of nitrite and nitrate, mass-spectrometry-based methods, notably gas chromatography-mass spectrometry (GC-MS), offer the highest reliability in terms of accuracy, precision, specificity, minimum of interferences, sensitivity, and no limitation regarding biological matrix. Among the GC-MS methods, that one utilizing the derivatization reagent pentafluorobenzyl bromide is the single assay permitting measurement of nitrite and nitrate. This method possesses the unique opportunity to measure simultaneously stable-isotope-labeled nitrite and nitrate (i.e. [15N]nitrite and [15N]nitrate), which are exclusively produced by NOS-catalyzed oxidation of L-[guanidino-15N2]-arginine, the stable-isotope-labeled L-arginine analog. *NOS may concomitantly produce *NO and O2*-, thus forming peroxynitrite (ONOO-), which also degrades to nitrite and nitrate. Thus, the GC-MS nitrite/nitrate assay provides information about biologically relevant NOS activity This chapter describes GC-MS protocols for the measurement of NOS activity in vitro (e.g., of isolated NOS preparations and in cells) and in vivo (in animals and humans).

Simultaneous measurement of urinary bisphenol A and alkylphenols by automated solid-phase extractive derivatization gas chromatography/mass spectrometry.

Bisphenol A (BPA) and alkylphenols (APs) are widely used industrial chemicals. BPA is used to manufacture polycarbonate plastic and epoxy resins; APs are used to make alkylphenol ethoxylates, common nonionic surfactants. BPA and APs can leach into the environment during industrial production and after degradation of the polycarbonate plastics and nonionic surfactants. Environmental exposure to these phenolic compounds has been associated with adverse reproductive and developmental effects in wildlife. We developed a sensitive and robust method for measuring BPA and six APs; 3-tert-butylphenol, 4-tert-butylphenol, 4-n-octylphenol, 4-tert-octylphenol, 4-n-nonylphenol, and technical-grade nonylphenol in urine. The method is based on the use of automated solid-phase extraction (SPE) coupled to isotope dilution-gas chromatography/mass spectrometry (GC/MS). During the automated SPE process, the phenols are both extracted from the urine matrix and derivatized, using pentafluorobenzyl bromide, on commercially available styrene-divinylbenzene copolymer-based SPE cartridges. After elution from the SPE column, the derivatized phenols in the SPE eluate are analyzed by GC/MS. The method, validated on spiked pooled urine samples and on urine samples from exposed persons, has limits of detection of approximately 0.1 ng in 1 mL of urine.