Assessment of occupational exposure to PAHs in an Estonian coke oven plant- correlation of total external exposure to internal dose measured as 1-hydroxypyrene concentration

The exposure of cokery workers to polynuclear aromatic hydrocarbons at an Estonian oil shale processing plant was assessed by using occupational hygiene and biomonitoring measurements which were carried out twice, in midwinter and in the autumn. To assess the external dose of polynuclear aromatic hydrocarbons, pyrene and benzo[a]pyrene concentrations were measured from the breathing zone of workers during a workshift. Skin contamination with pyrene and benzo[a]pyrene was assessed by skin wipe sampling before and after the workshift. As a biomarker of overall exposure to polynuclear aromatic hydrocarbons, and as an integral of all absorption routes of pyrene, 1-hydroxypyrene concentration was measured from post shift urine samples. Of the personal air samples, 18% exceeded the Finnish threshold limit value of benzo[a]pyrene (10 μg m^-3). Mean value (two separate measurements together) for benzo[a]pyrene was 5.7 μg m^-3 and for pyrene, 8.1 μg m^-3. Based on skin wipe sample analyses, the skin contamination was also obvious. The mean value of benzo[a]pyrene in the samples collected after the shift was 1.2 ng cm^-2. Benzo[a]pyrene was not found in control samples. The mean value of urinary 1-hydroxypyrene concentration was 6.0 μmol mol^-1 creatinine for the exposed workers and 0.5 μmol mol^-1 creatinine for the controls. This study undoubtedly shows the usefulness of 1-hydroxypyrene as an indicator of internal dose of polynuclear aromatic hydrocarbons. It can be concluded that the cokery workers at the Kohtla-Järve plant are exposed to high concentrations of polynuclear aromatic compounds, and the exposure level is considerably higher during the winter measurements.     

Fluoranthene determination based on a rapid and sensitive syringe extraction and solid-phase fluorescence technique

A rapid and sensitive strategy was proposed for the detection of fluoranthene (FL), which is a polycyclic aromatic hydrocarbon (PAH), in water samples. In this work, syringe solid-phase extraction (SPE) combined with solid-phase fluorescence spectrometry was used to determine FL in PAHs polluted environmental samples. The fluorescence signals were directly monitored on the membrane surface after FL was enriched by syringe SPE. Under the optimal conditions, the proposed method showed a linear relationship in the concentration range 2–50 μg/L with a correlation coefficient (R²) of 0.998, and the limit of detection was 0.143 μg/L. The recoveries varied from 93.47% to 109.81% in the actual samples, with the relative standard deviations (n = 3) ranging from 2.06% to 6.32%. According to the results, the established method can be applied in the field of rapid detection as it is fast, simple, portable, and highly sensitive, and has strong anti-interference.     

BTEX Exposures among Automobile Mechanics and Painters and Their Associated Health Risks

We measured the concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) in the ambient air of automobile repair garages in Montreal, Canada, using the direct atmospheric pressure chemical ionization-tandem mass spectrometry (APCI-MS/MS) method. Among all the air samples analyzed, toluene was the most abundant BTEX-species (127–1101 μg/m³) followed by xylenes (50–323 μg/m³), ethylbenzene (11–65 μg/m³), and benzene (9.2–23 μg/m³). BTEX levels where ventilation was controlled simultaneously by both mechanical and natural systems were significantly less than levels at garages where only natural ventilation was used. Results suggest that multiple sources contribute to the occupational exposure of automobile mechanics and painters to the BTEX. Owing to the toxic effects of these chemicals, both chronic non-cancer hazard and integrated lifetime cancer risk due to the exposure of this occupational group were assessed. The levels of the BTEX measured at all the garages were less than the established limits for occupational exposure; still, benzene levels pose a potential cancer risk for the workers. At the prevailing levels of BTEX, they may not cause any chronic non-cancer problems for the workers.     

alpha-Fluoro beta alanine in urine of workers occupationally exposed to 5 fluorouracil in a 5 fluorouracil producing factory

Because of possible harmful health effects increased attention is being paid to the occupational exposure to cytostatic drugs of workers in hospitals and industry. In this study a biomarker for exposure to 5-fluorouracil (5FU) based on GC-MSMS was applied to study the occupational exposure of four workers in a pharmaceutical factory producing 5FU. The four workers all excreted-fluoro--alanine (FBAL), a metabolite of 5FU, via the urine (range excretion rates: 0-88 9 g per 8h). This is in accordance with the presence of 5FU and/or its precursor ethoxyfluorouracil (EFU) in stationary and personal air wipe samples taken from the the workplace.     

Preanalytical errors on zinc concentrations caused by single-use gloves

Preanalytical errors causing specimen contamination with zinc (Zn) are disastrous for routine medical diagnostics or scientific studies. The aim of the study presented here is to simulate contamination possibilities when using single-use gloves.The ability to release Zn into the specimen was tested using nitril (A), vinyl (B) and latex (C) gloves with 15 (14) replications. In our first approach, a 1 × 1 cm piece of the glove’s fingertip was incubated for 10 min with serum. Our second approach imitated a very short contact of serum to the glove’s material by letting serum run over the glove from a pipette for 3 cm distance into a tube. The effect of gloves’ contact to liver tissue was examined using glove C only: a block of liver tissue was touched once at one side producing an experimental fingerprint. Zn was analyzed in serum and liver wet weight (ww) using ICP-MS; the basal serum/liver Zn concentration was set as zero for calculation. The calculated addition of Zn is given as median (p25 - p75).The first approach led to distinct contamination with Zn (in μg/L) being evident from all three types of gloves, but depended markedly from the type of material: A: 176.5 (129.7–204); B: 975.1 (663.6–1164.3); C: 2112 (1685–2516). Imitating a very short contact of serum to the glove’s surface resulted in an additional Zn concentration of 105.7 (70.4–168.8), 56.2 (-13.5–121.4) and 955.7 (746–1159) μg/L using gloves A, B and C, respectively. A single fingerprint on liver tissue using glove C resulted an addition of 3995 (861–6435) μg Zn/kg liver ww.The data underline that the dimension of preanalytical contamination of blood and tissue samples for Zn analysis via single-use gloves is relevant for routine diagnostics and scientific studies. Critical steps and possibilities to minimize these effects should be considered seriously for specimen handling in routine laboratory diagnostics as well as in scientific studies to avoid preanalytical errors and, finally, misinterpretation of the data.     

alpha-Fluoro beta alanine in urine of workers occupationally exposed to 5 fluorouracil in a 5 fluorouracil producing factory

Because of possible harmful health effects increased attention is being paid to the occupational exposure to cytostatic drugs of workers in hospitals and industry. In this study a biomarker for exposure to 5-fluorouracil (5FU) based on GC-MSMS was applied to study the occupational exposure of four workers in a pharmaceutical factory producing 5FU. The four workers all excreted-fluoro--alanine (FBAL), a metabolite of 5FU, via the urine (range excretion rates: 0-88 9 g per 8h). This is in accordance with the presence of 5FU and/or its precursor ethoxyfluorouracil (EFU) in stationary and personal air wipe samples taken from the the workplace.     

Analysis of imidazoles and triazoles in biological samples after MicroExtraction by packed sorbent

This paper reports the MEPS-HPLC-DAD method for the simultaneous determination of 12 azole drugs (bifonazole, butoconazole, clotrimazole, econazole, itraconazole, ketoconazole, miconazole, posaconazole, ravuconazole, terconazole, tioconazole and voriconazole) administered to treat different systemic and topical fungal infections, in biological samples. Azole drugs separation was performed in 36?min. The analytical method was validated in the ranges as follows: 0.02–5?μg mL^?1 for ravuconazole; 0.2–5?μg mL^?1 for terconazole; 0.05–5?μg mL^?1 for the other compounds. Human plasma and urine were used as biological samples during the analysis, while benzyl-4-hydroxybenzoate was used as an internal standard. The precision (RSD%) and trueness (Bias%) values fulfill with International Guidelines requirements. To the best of our knowledge, this is the first HPLC-DAD procedure coupled to MEPS, which provides the simultaneous analysis of 12 azole drugs, available in the market, in human plasma and urine. Moreover, the method was successfully applied for the quantitative determination of two model drugs (itraconazole and miconazole) after oral administration in real samples.     

Health risk assessment from dermal exposure to pesticide residues on vegetables among greengrocers in fresh market,Bangkok, Thailand

Pesticide residues (PRs) in market vegetables have been reported regularly. Greengrocers may be exposed to several sorts of PRs on vegetables through hand contact. Health risk assessment from occupational exposure to PRs on vegetables is particularly concerning. This study was conducted among 91 vegetable vendors at a large fresh market in Bangkok. Hand wipe samples were collected in the dry season to extract and analyze PRs including organophosphates (OPs), pyrethroids (PYs), and carbamates (CAs) by gas chromatography (GC-FPD/GC-μECD) and liquid chromatography (LC–MS). The results showed that all wipe samples contained OPs, PYs, and CAs, mainly chlorpyrifos (0.01–0.14 µg/hands) and cypermethrin (0.42–11.64 µg/hands). The frequently detected PRs were aldicarb (87.2%), carbofuran (69.2%), permethrin (63.7%), and profenofos (60.0%). At 99th percentile values of PR exposure, average daily dose was 2.42 × 10^?5 mg/kg/d and hazard index did not exceed the acceptable level (0.287). Glove wearing, hand washing, and work-related factors were significantly associated with PRs on hands after adjusted for gender (p-value < 0.05). Greengrocers may therefore not be at risk from PRs on vegetables and exposure via hands during their work. However, these findings suggest that proper personal hygiene practices among greengrocers should be considered to prevent them from PR exposure and potential health risks.     

Quantitation of the antitumor agent N-(Phosphonacetyl)-l-aspartic acid in human plasma and urine by gas chromatography—mass spectrometry—selected ion monitoring

N-(Phosphonacetyl)-l-aspartic acid (PALA) is an antitumor agent which is currently under clinical study. A gas chromatography—mass spectrometry—selected ion monitoring assay procedure using [¹³C]PALA as the internal standard has been developed for the quantitation of PALA in biological samples. Standard curves which related ion intensity peak height ratios (m/e 220/221) to PALA concentrations in plasma and urine were described by a non-linear least square analysis with correlation coefficients of R² > 0.995 and > 0.996, respectively. Over concentration ranges for PALA of 1–60 μg/ml of plasma and 1–160 μg/ml of urine the coefficient of variation from the fitted curve was 4–18%. This methodology has been used to quantitate PALA in human plasma samples in a study on the clinical pharmacology of the drug.     

Microassay for primidone and its metabolites phenylethylmalondiamide,phenobarbital and p-hydroxyphenobarbital in human serum,saliva, breast milk and tissues by gas chromatography—mass spectrometry using selected ion monitoring

A method for the quantitative determination of primidone and its metabolites phenobarbital, phenylethylmalondiamide (PEMA) and hydroxyphenobarbital (free and conjugated) in serum, urine, saliva, breast milk and tissue has been developed. Following the addition of the methyl analogues of primidone, phenobarbital and PEMA as internal standards and of saturated ammonium sulphate, the samples (5–100 μl) were extracted twice with ethyl acetate—benzene (20:80). The extracts were divided into two equal portions; one portion was ethylated by Greeley's method for the analysis of primidone, phenobarbital and hydroxyphenobarbital, while the other was trimethylsilylated for the analysis of primidone and PEMA. A gas chromatographic—mass spectrometric system was used for the analysis of the derivatized extracts. Linear calibration curves were obtained in the concentration range studied (between 100 ng/ml and 30 μg/ml). The recoveries of the drugs were between 80 and 93%. The relative standard deviations were between 3.2 and 5.9% (100-μl serum samples containing 1 μg/ml of the drugs). The lower detection limits were found to be between 1.4 and 3.7 ng/ml using serum samples of 100 μl.These methods have been applied to the study of the placental transfer and neonatal disposition of primidone and its metabolites in the human.     

Improved method for identifying and quantifying olive oil phenolic compounds and their metabolites in human plasma by microelution solid-phase extraction plate and liquid chromatography–tandem mass spectrometry

Two methods based on solid-phase extraction (SPE) using traditional cartridges and microelution SPE plates (μSPE) as the sample pre-treatment, and an improved liquid chromatography coupled to tandem mass spectrometry (UPLC–MS/MS) were developed and compared to determine the phenolic compounds in virgin oil olive from plasma samples. The phenolic compounds studied were hydroxytyrosol, tyrosol, homovanillic acid, p-coumaric acid, 3,4-DHPEA-EDA, p-HPEA-EDA, luteolin, apigenin, pinoresinol and acetoxypinoresinol. Good recoveries were obtained in both methods, and the LOQs and LODs were similar, in the range of low μM. The advantage of μSPE, in comparison with SPE cartridges, was the lack of the evaporation step to pre-concentrate the analytes. The μSPE-UPLC–ESI-MS/MS method developed was then applied to determine the phenolic compounds and their metabolites, in glucuronide, sulphate and methylated forms, in human plasma after the ingestion of virgin olive oil.     

Ultrafiltration-light absorption spectrophotometric determination of silicon in blood

An ultrafiltration-light absorption spectrometric method for soluble molybdate-reactive silicon was assessed and applied to bovine and ovine blood plasma and sera, giving precise analytical results. Interfering protein above molecular weight 10,000–25,000 was removed by ultrafiltration, and silicon in ultrafiltrates was quantitated by measuring light absorption at 810 nm of the 1,2,4-aminonaphthol sulfonic acid/ascorbic acid-reduced silicomolybdate. Chemical interferences on the color-forming reaction of remaining blood components were tested by measuring recoveries of silicon added to real blood plasma samples and to synthetic blood plasma solutions, the latter containing typical levels of the major ions Na⁺, K⁺, Ca²⁺, HCO₃^?, and Cl^?, together with varying quantities of the potential interferants (amount per analytical reaction): phosphate (0–0.5 mg P), ferric ion (0–3 mg), fluoride (0–1.25 mg), vanadate (0–0.5 mg V), arsenate (0–10 μg As), and germanate (0–0.5 μg Ge). The mean recovery of added 0.8–9 μg silicon/g of bovine and ovine plasma was 97.7% (SE = 1.0, n = 17); the mean recovery of 1 and 5 μg silicon from synthetic blood plasma solutions with interferant levels up to 50-fold that in normal plasma was 99.2% (SE = 0.3, n = 47). Silicon concentrations found in bovine and ovine blood plasma and sera were typically around 7 μg/ml with procedural reagent blanks consistently low at a mean of 0.12 μg/test (SD = 0.011, n = 20). The silicon level in Center for Disease Control bovine serum (reference specimen Lot R-2274) was found to be (mean ± SE, n = 10) 1.147 ± 0.013 μg/g or 1.172 ± 0.013 μg/ml (25°C). The method detectivity (detection limit) was estimated at 0.03 μg.     

Determination of puerarin in biological samples and its application to a pharmacokinetic study by flow‐injection chemiluminescence

A simple and sensitive flow injection–chemiluminescence (FI–CL) method has been developed for the determination of puerarin, based on the fact that puerarin can greatly inhibit CL of the luminol–H₂O₂–haemoglobin system. The inhibition of CL intensity was linear to the logarithm of the concentration of puerarin in the range 0.08–10.0 μg/mL (r² = 0.9912). The limit of detection was 0.05 μg/mL (3σ) and the relative standard deviation (RSD) for 1.0 μg/mL (n = 11) of puerarin solution was 1.4%. Coupled with solid‐phase extraction (SPE) as the sample pretreatment, the determination of puerarin in biological samples and a preliminary pharmocokinetic study of puerarin in rats were performed. The recoveries for plasma and urine at three different concentrations were 89.2–110.0% and 91.4–104.8%, respectively. The pharmacokinetics of puerarin in plasma of rat coincides with the two‐compartment open model. The T_1/2α, T_1/2β, CL/F, V_Z/F, AUC_{(0 – t)}, MRT_{(0 – ∞)}, T_max and C_max were 0.77 ± 0.21 h, 7.55 ± 2.64 h, 2.43 ± 1.02 L/kg/h, 11.40 ± 3.45 L/kg, 56.67 ± 10.65 mg/h/L, 5.04 ± 2.78 h, 1.00 ± 0.35 h and 19.70 ± 4.67 μg/mL, respectively. Copyright © 2011 John Wiley & Sons, Ltd.     

Automated preparation and analysis of barbiturates in human urine using the combined system of PrepStation and gas chromatography–mass spectrometry

A system for an automatic sample preparation procedure followed by on-line injection of the sample extract into a gas chromatography–mass spectrometry (GC–MS) system was developed for the simultaneous analysis of seven barbiturates in human urine. Sample clean-up was performed by a solid-phase extraction (SPE) on a C₁₈ disposable cartridge. A SPE cartridge was preconditioned with methanol and 0.1 M phosphate buffer. After loading a 1.5 ml volume of a urine sample into the SPE cartridge, the cartridge was washed with 2.5 ml of methanol–water (1:9, v/v). Barbiturates were eluted with 1.0 ml of chloroform–isopropanol (3:1, v/v) from the cartridge. The eluate (1 μl) was injected into a GC–MS system. The calibration curves, using an internal standard method, demonstrated a good linearity throughout the concentration range from 0.02 to 10 μg/ml for all barbiturates extracted. The proposed method was applied to several clinical cases. The total analysis time for 20 samples was approximately 14 h.     

Determination of Human Exposure to Lead and Cadmium: A WHO/UNEP Pilot Study

Abstract

In Stockholm, methods for measuring exposure to lead and cadmium from air, food and beverages were studied in 1988 in a group of 15 non-smoking women, as part of the WHO/UNEP HEAL programme. Airborne particles in the breathing zone air (24-hour samples), duplicate diets (24-hour samples), and faeces (all the stools produced) were collected during 7 consecutive days. Blood was sampled before and immediately after the study period. The results confirmed the need for personal monitoring in the assessment of human exposure to lead and cadmium via air and food. There is need for suitable equipment for 24-hour personal air monitoring. On average, dietary lead (26 μg day^?1, SD 7.9) contributed more than 80% of the total lead uptake, while dietary cadmium (8.5 μg day^?1 SD 2.1) contributed about 99% of the total cadmium uptake. Occasionally consumed foodstuffs with high levels of lead or cadmium seemed to be responsible for a large part of the total weekly intake of lead and cadmium. Fecal lead and cadmium were found to be useful indicators of the total amounts of these metals ingested. Due to the large day-to-day variation observed in the dietary intake of lead and cadmium, the sampling period for duplicate diets and faeces should be at least 5–6 days.     

Development of a urinary free cortisol assay using solid-phase extraction–capillary electrophoresis

In clinical practice, the measurement of urinary free cortisol (UFC) provides the most sensitive and specific diagnostic information for excess adrenal production of cortisol. The existing methodologies (RIA and HPLC) are time consuming, costly, involve tedious extractions, derivatizations and problems with non-specific interactions with cortisol metabolites in urine. In the present study, we describe the development of an SPE–CE method for the rapid analysis of UFC. UFC was concentrated using SPE C₁₈ cartridges (3M Empore) under a vacuum and eluted with acetonitrile–SDS. The use of 10% acetone to wash cartridges before final elution with acetonitrile–SDS showed significant improvements in the free cortisol recovery. The complete extraction was accomplished in 10–15 min with a recovery of 89–94%. CE analysis was done on a Beckman P/ACE 5010 with detection at 254 nm using a neutral capillary. Detection limits of free cortisol in urine was improved to 10 μg/l with SPE compared to 500 μg/l without SPE. No interferences either from BSA or other urinary cortisol metabolites affected the free cortisol determinations. The results showed the feasibility of a rapid UFC detection with improved sample handling capacity.     

High-performance liquid chromatographic assay for the measurement of melphalan and its hydrolysis products in perfusate and plasma and melphalan in tissues from human and rat isolated limb perfusions

A sensitive, specific and rapid reversed-phase high-performance liquid chromatographic (HPLC) assay was developed for the quantitation of melphalan and its hydrolysis products in samples from the isolated perfusion of human and rat limbs. Samples of perfusate, plasma and tissue were analysed, following methanol precipitation, using a phenyl column and fluorescence detection. Dansyl-arginine (38 μg ml⁻¹) was employed as the internal standard. Good resolution was observed allowing quantitation of melphalan, monohydroxymelphalan (MOH) and dihydroxymelphalan (DOH) in perfusate and plasma and melphalan in tissue. The mean recoveries of melphalan, MOH and DOH from perfusate and plasma were all 100 ± 10%. The recovery of melphalan in tissue was 93.5%. A linear response was demonstrated for melphalan in the concentration range 1.8–56.8 μg ml⁻¹, for DOH in the concentration range 0.5–30.0 μg ml⁻¹ and for MOH in the range 1.4–25.1 μg ml⁻¹, in perfusate and plasma. The lower limits of quantitation of melphalan, MOH and DOH in perfusate and plasma were 1.4, 2.4 and 1.2 ng on column, respectively, and 7.2 ng of melphalan on column in tissue. Intra-assay coefficients of variation (C.V.) for melphalan, MOH and DOH, at low and high concentrations were all less than 5% and the inter-assay C.V.s were less than 9%. An ultra-filtration study to determine the protein binding of melphalan and the hydrolysis products showed that the unbound fractions (f_u) of melphalan in buffer containing dextran and bovine serum albumin were 0.873 and 0.521, respectively. The assay was used to quantitate melphalan and its hydrolysis products in samples from isolated perfusions in the human limb and rat hindlimb.     

米非司酮对胰腺癌细胞耐药株Patu8988/FU 的逆转作用

目的:研究米非司酮(mifepristone,MIF)对胰腺癌多药耐药细胞株Patu8988/FU耐药性的逆转作用。方法:采用四甲基偶氮唑盐(MTT)比色法检测MIF对胰腺癌细胞Patu8988及胰腺癌耐药细胞株Patu8988/FU增殖的影响,选择对两种细胞生长抑制率≤5%的浓度为其非细胞毒性剂量;观察非毒性剂量的MIF作用72 h后Patu8988/FU细胞对5-FU耐药性的逆转效果。结果:①MIF浓度≤10μmol.L-1对Patu8988及Patu8988/FU于细胞的增殖均无抑制作用(P>0.05);20μmol.L-1和40μmol.L-1MIF对Patu8988及Patu8988/FU于细胞的增殖均有抑制作用(P<0.05),MIF对Patu8988及Patu8988/FU细胞增殖具有剂量依赖性;②加入梯度浓度5-FU后Patu8988细胞和Patu8988/FU细胞的IC50分别为(2.394±0.011)μg.ml-1、(49.87±4.026)μg.ml-1(P<0.01),耐药倍数为20.83;Patu8988及Patu8988/FU细胞加入5-FU后分别与2.5μmol.L-1、5μmol.L-1、10μmol.L-1MIF共同孵育72h后,Patu8988/FU细胞对5-FU耐药性的逆转倍数分别为1.42、1.71、3.10;Patu8988/FU对5-FU的敏感性明显增加(P<0.05),而Patu8988细胞对5-FU的敏感性并未改变(P>0.05)。结果还显示MIF作用后Patu8988/FU对5-FU的敏感性变化具有剂量依赖性。结论:MIF对胰腺癌多药耐药细胞株Patu8988/FU耐药性的有逆转作用。     

Chiral Assay of Atenolol Present in Microdialysis and Plasma Samples of Rats Using Chiral CBH as Stationary Phase

Two different enantioselective chiral chromatographic methods were developed and validated to investigate the disposition of the β₁-receptor antagonist atenolol in blood and in brain extracellular fluid of rats (tissue dialysates). System A for the plasma samples was a one-column chromatographic system with a Chiral CBH column with an aqueous buffer as mobile phase into which cellobiose was added for selective regulation of the retention of the internal standard, (S)-metoprolol. The plasma samples were analysed after a simple extraction procedure. The limit of quantitation was 0.2 μg/ml for the atenolol enantiomers. The repeatability of the medium concentration quality control plasma sample (6.0 μg rac-atenolol/ml) was 11–18% for the enantiomers. The dynamic linear range of the plasma samples was 0.5–20 μg/ml. For system B, since atenolol is an extremely hydrophilic drug, the tissue dialysate sample required a much more sensitive system as compared to the plasma samples. A coupled column system was used for peak compression of the enantiomers in the eluate after the separation on the Chiral CBH column, hence increasing the detection sensitivity. The limit of quantification was 0.045 μg/ml for the atenolol enantiomers in artificial CSF. The repeatability of the medium concentration quality control samples (0.1 and 4.0 μg rac-atenolol/ml in artificial CSF and Hepes Ringer, respectively) was 2.8–9.3% for the two enantiomers. The dynamic linear range of the brain samples was 0.05–1.0 and 0.5–20 μg/ml in artificial CSF and Hepes Ringer, respectively. Chirality 9:329–334, 1997. © 1997 Wiley-Liss, Inc.     

Biological monitoring of occupational exposure to 5-fluorouracil: Urinary α-fluoro-β-alanine assay by high performance liquid chromatography tandem mass spectrometry in health care personnel

A new sensitive and specific HPLC–MS/MS method for the determination of α-fluoro-β-alanine (FBAL), the main metabolite of the antineoplastic drug 5-fluorouracil (5-FU), in urine for the biological monitoring survey of health care workers exposed to 5-FU is described. This procedure is characterized by a pre-column FBAL derivatization by 2,4-dinitrofluorobenzene followed by solid phase extraction sample clean-up. The chromatographic separation was achieved by hydrophilic interaction chromatography (HILIC) on a ZIC HILIC column (Sequant) and the quantification was performed by tandem mass spectrometry. The method offers high sensitivity with a quantification limit of 1 μg/l, which is an improvement on those previously reported. The within- and between-day precisions were less than 13% and 15% respectively at the LOQ and no significant relative matrix effect was observed for FBAL. The validated method was applied to the biological monitoring of occupational exposure to 5-FU in a French hospital. Pre- and post-shift urine samples were collected from 19 workers in a hospital pharmacy and an oncology ward over a period of 5 days. On a total of 121 analysed samples, measurable amounts of FBAL were detected in up to 29%, the concentrations range from LOQ to 22.7 μg/l, yielding evidence of occupational exposure to 5-FU. Such data are scarce and represent a step forward in assessing the occupational health risks associated with handling antineoplastic drugs.