Table 1.

Methods previously implemented for extraction of ambient PM_2.5 for use in toxicology studies.

Removal method	Solvent	Concentration	Authors
Sonication
	Water	N/A	Huang et al. (2003), Schins et al. (2004), Rivero et al. (2005), Riva et al. (2011), and Deng et al. (2013)
		Lyophilization	Vincent et al. (1997), Monn and Becker (1999), Baulig et al. (2004), and Geng et al. (2006)
		Desiccator	Watterson et al. (2007), Gualtieri et al. (2012), and Longhin et al. (2013)
		Vacuum centrifuge	Huang et al. (2014)
		Dilution	Schaumann et al. (2004)
		Vacuum and desiccator	Valavanidis et al. (2005)
	Methanol	Rotary evaporator	Jalava et al. (2006, 2009), Gerlofs-Nijland et al. (2007), Happo et al. (2010, 2013), Verma et al. (2012), and Janssen et al. (2014)
	Toxicology media	N/A	Long et al. (2001), Akhtar et al. (2010, 2014), and Kumar et al. (2015)
	PBS	Lyophilization	Choi et al. (2004)
Probe sonication
	Methanol	N2 blow down	Mudway (2004) and Godri et al. (2011)
	Toxicology media	N/A	Imrich et al. (2000) and Ning et al. (2000)
Soxhlet extraction
	DCM	Evaporation	de Kok et al. (2005)
	And methanol	Evaporation	Skarek et al. (2007)
	And water	Rotary evaporator	Cavanagh et al. (2009)
Agitation
	Water	Lyophilization	Dye et al. (2001)

Removal method, solvent type, concentration, and authors are listed for toxicological assessments of ambient PM_2.5 using filter extraction.