Determination of airborne trialkyl and triaryl organophosphates originating from hydraulic fluids by gas chromatography-mass spectrometry. Development of methodology for combined aerosol and vapor sampling.

Methodology for personal occupational exposure assessment of airborne trialkyl and triaryl organophosphates originating from hydraulic fluids by active combined aerosol and vapor sampling at 1.5L/min is presented. Determination of the organophosphates was performed by gas chromatography-mass spectrometry. Combinations of adsorbents (Anasorb 747, Anasorb CSC, Chromosorb 106, XAD-2 and silica gel) with an upstream cassette with glass fiber or PTFE filters and different desorption/extraction solvents (CS(2), CS(2)-dimethylformamide (50:1, v/v), toluene, dichloromethane, methyl-t-butyl ether and methanol) have been evaluated for optimized combined vapor and aerosol air sampling of the organophosphates tri-isobutyl, tri-n-butyl, triphenyl, tri-o-cresyl, tri-m-cresyl and tri-p-cresyl phosphates. The combination of Chromosorb 106 and 37 mm filter cassette with glass fiber filter and dichloromethane as desorption/extraction solvent was the best combination for mixed phase air sampling of the organophosphates originating from hydraulic fluids. The triaryl phosphates were recovered solely from the filter, while the trialkyl phosphates were recovered from both the filter and the adsorbent. The total sampling efficiency on the combined sampler was in the range 92-101% for the studied organophosphates based on spiking experiments followed by pulling air through the sampler. Recoveries after 28 days storage were 98-102% and 99-101% when stored at 5 and -20 degrees C, respectively. The methodology was further evaluated in an exposure chamber with generated oil aerosol atmospheres with both synthetic and mineral base oils with added organophosphates in various concentrations, yielding total sampling efficiencies in close comparison to the spiking experiments. The applicability of the method was demonstrated by exposure measurements in a mechanical workshop where system suitability tests are performed on different aircraft components in a test bench, displaying tricresyl phosphate air concentrations of 0.024 and 0.28 mg/m(3), as well as during aircraft maintenance displaying tri-n-butyl phosphate air concentrations of 0.061 and 0.072 mg/m(3).

Solvent exposures at shoe factories and workshops in Hebron City, West Bank.

Exposure to organic solvents has been reported to increase the risks for acute and chronic health effects among shoe industry workers. In developing countries, protection against chemical exposures is often not provided. The study was conducted to identify working conditions and estimate the concentrations of organic solvents used in shoe factories and workshops in Hebron City. Personal interviews containing questions related to personal protective equipment (PPE) were used to identify working conditions, and samples collected from factories and workshops were analyzed using gas chromatography. Geometric means (GMs) were calculated for the solvents. Six major organic solvents were detected in the factories. Acetone (GM = 51.5 mg/m3, GSD = 3.82) was common in gluing tasks. Dichloromethane (GM = 47 mg/m3, GSD = 2.62) was common in cleaning tasks. Heptane, methylethyl ketone, n-hexane, and toluene were common in gluing tasks. Four major organic solvents were detected in the workshops: acetone (GM = 32.3 mg/m:3, GSD = 6.33), toluene (GM = 70.3 mg/m3, GSD = 3.06), n-hexane (GM = 19.4 mg/m3:, GSD = 2.65), and methylethyl ketone (GM = 130 mg/mM3, GSD = 1.5). 81% of the factory workers had never used respiratory protective equipment, and 92% had never used work clothes. 97% of the workers in the workshops had never used respiratory protective equipment, 94% had never worn gloves, and 90% had never used work clothes. Exposures to solvents in the absence of personal Protective equipment, tasks barriers, and mechanical ventilation can adversely affect health.

Determination of 1-(2-methoxyphenyl)piperazine derivatives of isocyanates at low concentrations by temperature-programmed miniaturized liquid chromatography.

A temperature-programmed packed capillary LC method with large-volume injection on-column focusing has been developed for screening and determination of 1-(2-methoxyphenyl)piperazine derivatives of airborne toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylenediisocyanate and methylenebisphenyl-4,4-diisocyanate, based on sampling methods described in MDHS 25/3. Injection volumes up to 100 microl were successfully loaded onto the 250x0.32 mm I.D. capillary column packed with 3 microm Hypersil ODS particles. The isocyanate derivatives were loaded at 10 degrees C and eluted by a three-step temperature program starting at 10 degrees C for 10 min, followed by a temperature ramp of 2.5 degrees C min(-1) to 45 degrees C and then 9.9 degrees C min(-1) to 90 degrees C. The mobile phase consisted of acetonitrile-acetate buffer (3% triethylamine, pH 4.5) (45:55, v/v). The isocyanate derivatives were dissolved in acetonitrile-acetate buffer (3% triethylamine, pH 4.5) (30:70, v/v) to achieve sufficient focusing. The concentration limit of detection of the individual derivatives utilizing an "U" shaped flow cell with a 8.0 mm light path and an injection volume of 100 microl was 44, 87, 43 and 210 pg ml(-1) for toluene-2,6-diisocyanate, hexamethylenediisocyanate, toluene-2,4-diisocyanate and methylenebisphenyl-4,4-diisocyanate, respectively. Within the investigated concentration range, 10-500 ng ml(-1), the linear calibration curves gave correlation coefficients ranging from 0.994 to 0.998. The repeatability of the method with regard to retention time and peak height ranged from 0.3 to 1.1% and 1.1 to 2.3% (n=9) relative standard deviation, respectively. The average recovery of the method, with regard to toluene-2,4-diisocyanate, was 97.7+/-1.6% (n=9).