AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Development of a Thoracic Personal Sampler System for Co-Sampling of Sulfuric Acid Mist and Sulfur Dioxide Gas
CHIH-HSIANG CHIEN, Alexandros Theodore, Chang-Yu Wu, Yu-Mei Hsu, Brian Birky, University of Florida
Abstract Number: 243 Working Group: Instrumentation and Methods
Abstract A novel personal sampler has been designed to measure inorganic acid mists and gases in workplaces for determining human exposure levels to these acids. This sampler consists of a parallel impactor for classifying aerosols with size following ISO/CEN/ACGIH defined human thoracic fraction, a cellulose filter to collect the residual sulfuric acid mist but allowing penetration of sulfur dioxide gas, and an accordion-shaped porous membrane denuder (aPMD) for adsorbing the penetrated sulfur dioxide gas. To minimize sampling interference, antistatic PTFE is selected as the housing material as it is inert and is easy to machine. The novel flat design is easily adaptable to a light-weight and portable device that an individual could carry.
Monodisperse aerosol generated from a vibrating orifice aerosol generator and sulfur dioxide gas from a cylinder were used to test the performance of the personal sampler. The results showed the parallel impactor operated at 2 Lpm flow rate had a cutoff size of 10.2 µm and its penetration curve agreed well with the defined thoracic fraction. 94% sampling bias is within 10% for particle size distributions with MMAD between 1 – 25 micro-meter and GSD between 1.75 – 4, which meets the criteria of the EN 13205 standard. The aPMDs maintained a gas collection efficiency greater than 95% for 4 hours when sampling 10 ppm of sulfur dioxide gas, demonstrating that the aPMD meets the criteria for collection efficiency and collection capacity. While the aPMD has similar performance to popular annular or honeycomb denuders made of glass, this shatterproof aPMD is only half of the volume and 1/25th the weight of the honeycomb denuder. All the test results illustrate the aPMD is a more advantageous personal sampler that enables a more accurate assessment of human exposure to sulfuric acid aerosol in thoracic mass.