Table 1. MS-PECD asymmetry factor G * measured for the various mixtures and pure samples.

	Mass-tagged data		Non-mass-tagged data
Component	Limonene	Camphor	All ions	All ions
Ion Mass (m/z)	136	152
Electron Energy Range (eV)	0.0–0.5	0.4–0.8	0.0–0.5	0.4–0.8
Mix-RR	−0.022(9)	0.042(11)	−0.003(4)	0.023(5)
Mix-RS	−0.023(9)	−0.039(12)	−0.019(4)	−0.015(4)
Mix-S[Rs]	0.024(7)	0.022(9)	0.017(4)	0.020(4)
Pure R-limonene	−0.019(11)
Pure S-limonene	0.020(11)
Mean |G|	0.022(2)†	0.041(2)‡

^*G value derived by forward/backward differences in coincident electron counts, see equation 5. Quoted uncertainties (in brackets of last digits) are estimated assuming Poisson counting statistics and using standard error propagation. The filtered electron energy ranges are those shown shaded in Fig. 4b and Fig. 4c.

^†Mean absolute value of MS-PECD G for limonene obtained from the five values above. The sign corresponds to the value for S-limonene and ionization with LCP light. The s.d. of the sample (in brackets of last digits) is shown.

^‡Mean absolute value of MS-PECD G for camphor obtained from the two values above and excluding the value of the enantiomerically mixed camphor in Mix-S[Rs]. The sign corresponds to the value for R-camphor and ionization with LCP light. The s.d. of the sample (in brackets of last digits) is shown.