Table 10: Observed fractional abundances from literature.
Source HCN HCO⁺ SO

$\times 10^{-9}$ $\times 10^{-9}$ $\times 10^{-9}$

AFGL 2591 20.0^a 10.0^a 10.0^b

W3 IRS 5 2.0^c 0.73^c 10.0^b

IRAS 16293 1.1^d 1.4^d 4.4^d

N1333-I2 2.0^e 3.3^e 3.4^e

N1333-I4A 0.36^e 0.43^e 4.6^e

L1448-C 5.4^e 9.1^e 1.4^e

L483 2.0^e 2.0^e 0.29^e

L723 1.0^e 4.1^e 2.4^e

SMM4 2.0^f 1.0^f ...

L1489 0.65^e 18.0^e 2.0^e

^a van der Tak et al. (2000);
^b van der Tak et al. (2003);
^c Helmich et al. (1997);
^d Schöier et al. (2002);
^e Jørgensen et al. (2004);
^f Hogerheijde et al. (1999).

**Table 10:** Observed fractional abundances from literature.
Source	HCN	HCO⁺	SO
	$\times 10^{-9}$	$\times 10^{-9}$	$\times 10^{-9}$
AFGL 2591	20.0^a	10.0^a	10.0^b
W3 IRS 5	2.0^c	0.73^c	10.0^b
IRAS 16293	1.1^d	1.4^d	4.4^d
N1333-I2	2.0^e	3.3^e	3.4^e
N1333-I4A	0.36^e	0.43^e	4.6^e
L1448-C	5.4^e	9.1^e	1.4^e
L483	2.0^e	2.0^e	0.29^e
L723	1.0^e	4.1^e	2.4^e
SMM4	2.0^f	1.0^f	...
L1489	0.65^e	18.0^e	2.0^e

Source LaTeX | All tables | In the text