ConclusionUltrafine particles showed high PM concentrations from bio-mass burning, where the diameter range that was responsiblefor the highest PM concentrations was 0.0–0.4 μm (backupstage). The predominant ions in the PM collected using thenew portable isokinetic sampler were potassium (K+), chlo-ride (Cl − ) and nitrate (NO 3− ), with potassium and chloridestanding out as important ions in the characterization of bio-mass burning. The vast majority of these ions were present inPM smaller than 1.0 μm (B3). The Venturi scrubber developedoptimum fractional and overall collection efficiencies. For theAndersen cascade impactor, the highest efficiencies occurredfor the diameter ranges of 4.7–3.3 μm (S4) and 3.3–2.1 μm(S5) with maximum efficiencies of 94.3% and 90.6%. For thenew portable isokinetic sampler, the highest partial collectionefficiencies were obtained for Vth = 262 m/s and had valuesof 99.6% for PM greater than 2.5 μm (B1); 98.9% for PMbetween 1.0 and 2.5 μm (B2); and 75.2% for PM less than1.0 μm (B3). It was observed that the efficiencies, both frac-tional and overall, increased with the gas velocity at the Ven-turi throat. Thus, the best operating condition for the Venturiscrubber was Vth = 262 m/s with a water flow rate of 2.5 L/min. The performance of the Venturi scrubber was very sat-isfactory, especially as it was responsible for collecting 75.2%of PM1.0 (B3), which is the most dangerous to the respiratoryand cardiovascular systems. This shows that a compact, cheap,and practical piece of equipment for flare gas treatment, suchas the Venturi scrubber and the cost-effective and efficientportable samplers, can be very interesting for industries thatemit high concentrations of pollutants.