New automated and high-throughput quantitative analysis of urinary ketones by multifiber exchange-solid phase microextraction coupled to fast gas chromatography/negative chemical-electron ionization/mass spectrometry.

The present research is focused on automation, miniaturization, and system interaction with high throughput for multiple and specific Direct Immersion-Solid Phase Microextraction/Fast Gas Chromatography analysis of the urinary ketones. The specific Mass Spectrometry instrumentation, capable of supporting such the automated changeover from Negative Chemical to Electron Ionization mode, as well as the automation of the preparation procedure by new device called MultiFiber Exchange, through change of the fibers, allowed a friendly use of mass spectrometry apparatus with a number of advantages including reduced analyst time and greater reproducibility (2.01-5.32%). The detection limits for the seven ketones were less than 0.004 mg/L. For an innovative powerful meaning in high-throughput routine, the generality of the structurally informative Mass Spectrometry fragmentation patterns together with the chromatographic separation and software automation are also investigated.

Gas chromatographic determination of glutaraldehyde in the workplace atmosphere after derivatization with 0-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine on a solid-phase microextraction fibre.

Glutaraldehyde is used primarily in hospital environments for the disinfection of various instruments (e.g., endoscopes). We describe in this paper the measurement of glutaraldehyde in a hospital environment using solid-phase microextraction. The method includes, prior to sampling, the adsorption of O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine on to the fibre (with polydimethylsiloxane-divinylbenzene). The fibre is then exposed to air, after which desorption is performed in the GC injection port. This process results in the formation of a stable derivative of the glutaraldehyde that is suitable for chromatographic purposes and detectable with classical detection methods, such as flame ionisation and electron-capture detection. We demonstrate that the procedure of adsorption, thermal desorption and derivatization is robust and reproducible. We were able to detect concentrations of 60 microg/m3 (10 s sampling) or 6 microg/m3 (120 s sampling) by electron-capture detection, and 80 microg/m3 (120 s sampling) by flame ionisation detection. We compared our method to currently existing methods of glutaraldehyde measurement and highlighted several important advantages of the method.

Air monitoring and assessment of occupational exposure to peracetic acid in a hospital environment.

A new automated method based upon solid phase micro-extraction (SPME)/fast gas chromatography-mass spectrometry (GC-MS) was developed for the quantitative determination of airborne peracetic acid (PAA). The method is suitable for the quick assessment of brief acute exposure as well as for long-term environmental monitoring of PAA and can assist in improving safety and environmental quality in workplaces where disinfectants are used. During a monitoring campaign in the Regional Hospital of Florence, Italy, the 8-h average air concentration of PAA was 1/10 of the threshold limit value of time weighted average in 87% of the clinical units tested. However, the application of the new SPME method showed that short-term exposure to PAA could be relatively elevated in some hospital units with poor ventilation, allowing prompt intervention in order to reduce worker exposure to this potentially toxic compound.

Determination of organic acids in urine by solid-phase microextraction and gas chromatography-ion trap tandem mass spectrometry previous 'in sample' derivatization with trimethyloxonium tetrafluoroborate.

A method for the determination of the organic acids directly in the urine employing derivatization with trimethyloxonium tetrafluoroborate as a methylating agent and sequential extraction by head space and direct immersion/solid phase microextraction is reported. Furoic acid, hippuric acid, methylhippuric acid, mandelic acid, phenylglyoxylic acid and trans, trans muconic acid contained in urine and proposed by the American Conference of Governmental Industrial Hygienists as biological exposure indices were determined after a fast and economically convenient preparation step and sensitive gas chromatography-ion trap-mass spectrometry/tandem mass spectrometry analysis. Urine is rather a complex sample and hence the acquisition method required specific GC-MS instrumentation capable of supporting the changeover, fully automated during a single chromatographic separation, from mass to tandem mass spectrometry and both chemical and electron ionization modes. The automation of the analytical method provides a number of advantages, including reduced analysis time for both routine analysis and method development, and greater reproducibility. The equilibrium and kinetics of this substances vs head space/direct immersion-solid phase microextraction were investigated and evaluated theoretically.