Table 7: Column densities of the asymmetric aliphatic peaks in the region 2800-3000 cm^-1 present in the IDPs spectra after the HF treatment, and of the IRS 7 source of the Galactic Center. The estimated error of these values, due to spectral noise and the quality of the Gaussian fit, is $\sim$ 10%.
IDP area [CH₂]asym N[CH₂] area [CH₃]asym N[CH₃] N[CH₂]/N[CH₃]

$\sim$ 2922 cm^-1 (groups/cm²) $\sim$ 2958 cm^-1 (groups/cm²)

L2036-E19 - - - - -

L2021-K3 0.039 $1.1 \times 10^{16}$ 0.014 $2.6 \times 10^{15}$ 4.2

L2021-K2 0.059 $1.6 \times 10^{16}$ 0.016 $2.9 \times 10^{15}$ 5.5

L2011-F2 0.036 $1.0 \times 10^{16}$ 0.017 $3.2 \times 10^{15}$ 3.1

W7116B-N 0.071 $1.9 \times 10^{16}$ 0.037 $6.8 \times 10^{15}$ 2.8

W7116B-Y 0.121 $3.3 \times 10^{16}$ 0.050 $9.2 \times 10^{15}$ 3.6

W7116B-U 0.062 $1.7 \times 10^{16}$ 0.033 $6.1 \times 10^{15}$ 2.8

Average 3.7

IRS 7
9.64 $2.6 \times 10^{18}$ 6.68 $1.2 \times 10^{18}$ 2.2

**Table 7:** Column densities of the asymmetric aliphatic peaks in the region 2800-3000 cm^-1 present in the IDPs spectra after the HF treatment, and of the IRS 7 source of the Galactic Center. The estimated error of these values, due to spectral noise and the quality of the Gaussian fit, is $\sim$ 10%.
IDP	area [CH₂]asym	N[CH₂]	area [CH₃]asym	N[CH₃]	N[CH₂]/N[CH₃]
	$\sim$ 2922 cm^-1	(groups/cm²)	$\sim$ 2958 cm^-1	(groups/cm²)
L2036-E19	-	-	-	-	-
L2021-K3	0.039	$1.1 \times 10^{16}$	0.014	$2.6 \times 10^{15}$	4.2
L2021-K2	0.059	$1.6 \times 10^{16}$	0.016	$2.9 \times 10^{15}$	5.5
L2011-F2	0.036	$1.0 \times 10^{16}$	0.017	$3.2 \times 10^{15}$	3.1
W7116B-N	0.071	$1.9 \times 10^{16}$	0.037	$6.8 \times 10^{15}$	2.8
W7116B-Y	0.121	$3.3 \times 10^{16}$	0.050	$9.2 \times 10^{15}$	3.6
W7116B-U	0.062	$1.7 \times 10^{16}$	0.033	$6.1 \times 10^{15}$	2.8
Average					3.7
IRS 7	9.64	$2.6 \times 10^{18}$	6.68	$1.2 \times 10^{18}$	2.2

Source LaTeX | All tables | In the text

	1 Introduction
	2 Materials and methods
	3 Results
	4 Discussion
	5 Conclusions and perspectives
	References