. Author manuscript; available in PMC: 2015 Jun 25.

Published in final edited form as: Aerosol Air Qual Res. 2014 Dec;14(7):1939–1949. doi: 10.4209/aaqr.2013.10.0312

Table 2.

Extraction efficiency under designed extraction conditions.

Test	Extraction condition	Extraction buffer	%recovery of Cr(VI) (Mean ± SD, N = 3)
Test	Extraction condition	Extraction buffer	PbCrO₄	BaCrO₄
1	15 min Ramping to 95°C and holding for 1 hr, pressure less than 220 psi	3% Na₂CO₃-2% NaOH	95.0 ± 5.5%	78.0 ± 3.1%
2	15 min Ramping to 60°C and holding for 1 hr, pressure less than 200 psi		43.7 ± 8.3%	16.5 ± 5.4%
3	15 min Ramping to 95°C and holding for 40 min, pressure less than 200 psi		81.3 ± 1.8%	42.3 ± 0.5%

4	15 min Ramping to 95°C and holding for 1 hr, pressure less than 220 psi	1:2.5 diluted 3% Na₂CO₃-2% NaOH	62.8 ± 6.0%	57.2 ± 8.8%
5		1:5 diluted 3% Na₂CO₃-2% NaOH	55.1 ± 7.0%	39.5 ± 6.2%