Table 2.

PPG standards identified using paper spray mass spectrometry. The PPG mass spectrum was obtained with excitation and detection frequency range of 1.5 MHz.

PPG	Experimental m/z	Theoretical m/z	Mass measurement error (Δppm)	Mass resolving power (M/ΔM50%)	[C3O2H7(C3H6O)nC6H13O2+Na]+
	1666.17197	1666.17200	−0.02	22686	n = 25
	1724.21224	1724.21386	−0.94	23629	n = 26
	1782.25781	1782.25573	1.17	23817	n = 27
	1840.29829	1840.29760	0.37	23808	n = 28
	1898.34113	1898.33946	0.88	23139	n = 29
	1956.37992	1956.38133	−0.72	22968	n = 30
	2014.41937	2014.42319	−1.90	22638	n = 31
	2072.46849	2072.46505	1.66	21991	n = 32
	2130.50088	2130.50692	−2.84	21503	n = 33
	2188.55370	2188.54878	2.25	20679	n = 34
	2246.59219	2246.59065	0.69	19685	n = 35
	2304.63182	2304.63254	−0.31	17868	n = 36
	2362.67370	2362.67438	−0.29	16365	n = 37