Summary

Beryllium (Be) has many industrial uses due to its unique properties; however, it represents a health risk for workers exposed to it. Chronic beryllium disease (CBD), an occupational disease related to Be exposure, is the progression from a sensitization phase consisting of a specific immune response following Be exposure. The main Be absorption route is the inhalation of particles; however, skin penetration may be significant in the sensitization process.

Since the 1990s, the CSST has had to compensate many workers, resulting in a growing preoccupation about Be in workplaces. Periodic sampling is now required in environments where beryllium is known to be present. The Québec standard is 0.15 µg/m³ Be in the air for a time-weighted average exposure value, which requires the use of an analytical method with a low limit of detection. The IRSST has developed an analytical method using ICP-MS to reach such a limit. However, the use of this analytical technique is expensive. To make a method available that can be applied in workplaces where controls on the presence of beryllium are frequent, the molecular fluorescence technique was considered.

Fluorescence is a very sensitive technique, and portable instruments are commercially available. Beryllium determination by fluorescence is achieved by forming a complex with a ligand with fluorescence properties. 10-hydroxybenzo[h]quinoline-7-sulfonate forms a complex with beryllium that fluoresces at 475 nm. The intensity of the emission is linearly proportional to the Be concentration. Also, the ligand seems specific to Be since no other emission signal was observed in the presence of other cations. However, a high concentration of iron produces a decrease in the signal due to the precipitation of iron hydroxides in an alkaline medium. The dissolution tests performed with beryllium oxide (a practically insoluble species) and 1% NH₄HF₂ yielded recovery rates close to 96%. In addition, NH₄HF₂ is compatible with the reagent. A methodological limit of detection as low as 0.0002 µg/sample was achieved, allowing quantities below the Québec standard to be evaluated. The coefficients of variation of less than 4% obtained for replicability and repeatability for this method ensure good result accuracy. The fluorescence analytical method for beryllium determination is applicable to the air sampling method currently used by the IRSST.