Determination of benzene, toluene and N-hexane in urine and blood by headspace solid-phase microextration/gas-chromatography for the biomonitoring of occupational exposure

Abstract

A análise de tolueno, benzeno e n-hexano inalterados em urina e sangue humano é uma ferramenta para avaliar a exposição ocupacional a esses solventes. Um método simples usando microextração em fase sólida acoplada ao headspace (HS-SPME), usando fibras de carboxeno/ polidimetilsiloxano (CAR-PDMS) e PDMS, para análise simultânea por cromatografia gasosa de tolueno, benzeno e n-hexano em urina e em sangue foi desenvolvido com intuito de realizar a monitorização biológica de indivíduos expostos ocupacionalmente a esses solventes. O método foi aplicado na análise de amostras de trabalhadores que utilizavam colas, contendo solventes, na recuperação de calçados. O tolueno foi detectado em todas as amostras de sangue coletadas em sapatarias quando se utilizou a fibra de CAR-PDMS (16,0-55,2 mg L ). O benzeno não foi detectado em nenhuma das amostras de sangue e/ou urina. Nenhum dos solventes pode ser quantificado nas amostras de urina.Analysis of unchanged toluene, benzene and n-hexane in human blood and urine can be useful to evaluate occupational exposure to these solvents. A simple method was developed using headspace-solid phase microextraction (HS-SPME) for simultaneous gas-chromatography analysis of toluene, benzene and n-hexane in urine and blood; with purpose of biological monitoring of occupational exposure. Carboxen/polidimethylsiloxane fiber (CAR-PDMS) and PDMS fiber coating were employed in this analysis. Blood and urine samples were collected from handling glue workers. The toluene was detected in all blood samples collected from workers handling glue in shoe repair shops, when using CAR-PDMS fibers (16.0-55.2 mg L -1 , n=7). n-Hexane was only detected in two blood samples (33.0 and 41.3 mg L -1 ) and benzene was not detected in anyone. No solvent could be quantified in urine samples.

A pilot study on the stability of toluene in blood from workers

“…We suspect the reason why toluene is stable in blood is due to the influence of the hydrophobic matrix of the biological fluid. Toluene is a hydrophobic substance; therefore, it is suspected that toluene bonds with the lipids in blood, and that this hydrophobic effect explains why toluene in blood is not more evaporative during storage [13,14]. …”

A needle trap device packed with MIL‐100(Fe) metal organic frameworks for efficient headspace sampling and analysis of urinary BTEXs

“…Dynamic headspace GC-PID 0.015-0.035 0.030-0.060 9.5% Karačonji & Skender (2007) Headspace-purge and trap GC-PID 0.015-0.035 0.050-0.075 10.0% (Brči c & Skender, 2003) Headspace-PDMS-SPME GC-MS 0.035-0.050 0.050-0.08 11.0% (Karačonji & Skender, 2007) Headspace-CAR-PDMS-SPME GC-FID 0.002-0.010 0.003-0.012 13.0% (Gomes et al, 2010) Headspace-Ph, PDMS-CMV GC-MS 0.001-0.006 0.005-0.013 5.0% (Gura et al, 2018) Headspace-CF, CAR-PDMS-SPME GC-FID 0.0002-0.0007 0.007-0.02 9.6% (Tajik et al, 2017) Headspace-MIL-NTD GC-FID 0.0001-0.0005 0.0003-0.0014 7.6% Present RSD, Relative standard deviation; GC, gas chromatography; PID, photo ionization detector; PDMS, polydimethylsiloxane; SPME, solid-phase micro-extraction; MS, mass spectrometry; CAR, carboxen; FID, flame ionization detector Ph, phenyl; CMV, capillary microextraction of volatile; CF, cold fiber; NTD, needle trap device. previous studies for headspace extraction of BTEXs from the urine matrix.…”

“…Thus far, various analytical methods, such as dynamic headspace (Karačonji & Skender, 2007), headspace purge and trap (Brči c & Skender, 2003), headspace solid-phase micro-extraction (Gomes, D'Andrea, Mendes, & de Siqueira, 2010;Gura, Tarifa, Mulloor, Torres, & Almirall, 2018;Karačonji & Skender, 2007) and cooling/heating headspace solid-phase micro-extraction (Tajik, Bahrami, Ghiasvand, & Shahna, 2017), have been used for the determination of urinary BTEXs. solid-phase micro-extraction as a solvent-less, onestep, fast and cost-effective method has been used for the extraction and analysis of VOCs in urine.…”

Development and validation of residual solvent determination by headspace gas chromatography in Imatinib Mesylate API

“…However, depending on the nature of the API, residual solvents and drying condition of the process, some amount of residual solvents traces can be retained in the final drug substances or drug product. Thus, acceptable levels of many residual solvents are included in regulatory guideline; particularly in guideline Q3C issued by the International Conference on Harmonization of technical requirements for registration of pharmaceuticals for human use (ICH) [5,6]. ICH has also included daily exposure limit of many solvents it has classified these solvents into four classes on the basis of the toxicity level and the degree to which they can be considered an environmental hazard [6].…”

“…Thus, acceptable levels of many residual solvents are included in regulatory guideline; particularly in guideline Q3C issued by the International Conference on Harmonization of technical requirements for registration of pharmaceuticals for human use (ICH) [5,6]. ICH has also included daily exposure limit of many solvents it has classified these solvents into four classes on the basis of the toxicity level and the degree to which they can be considered an environmental hazard [6]. Class I solvents (which covers 5 residual solvents) are known or suspected human carcinogens and environmental hazards, the use of these solvents should be avoided.…”