\begin{table}%t4
%%\centering
\par
\caption{Aliphatic column density (noted $N$[3.4], in the region
3000$-$2800~cm$^{-1}$) and silicate column density ($N$[10], around 1000~cm$^{-1}$)
of  the IDPs before the HF treatment, calculated after baseline correction.  See text for error estimates.\label{SiO-preHF}}
 \begin{tabular}{cccccc}
        \hline\hline
        IDP & area [3.4]  & area [10] &  $N$[3.4]  & $N$[10]  & $N$[3.4]/$N$[10]    \\
	&  & & (aliph C~atom/cm$^{2}$)  & (Si atoms/cm$^{2}$)  & (aliph. C atoms/Si atoms)  \\
        \hline	
W7116B-N  & 0.11 & 2.3  & $2.1 \times 10^{16}$ &  $2.7 \times 10^{16}$ & 0.78 \\
W7116B-Y  & 0.43 & 5.2  & $8.2 \times 10^{16}$ &  $6.0 \times 10^{16}$  & 1.4 \\
W7116B-U  & 0.07 & 10.0 & $1.3 \times 10^{16}$ &  $1.2 \times 10^{17}$  & 0.11 \\
L2036-E19 & 0.11 & 5.0  & $2.1 \times 10^{16}$  & $5.9 \times 10^{16}$  &  0.36  \\
L2021-K3  & 0.12 & 3.6  & $2.3 \times 10^{16}$  & $4.2 \times 10^{16}$  & 0.55  \\
L2021-K2  & 0.05 & 3.0  & $9.6 \times 10^{15}$ &  $3.6 \times 10^{16}$ &  0.27 \\
L2011-F2  & 0.14 & 6.0  & $2.7 \times 10^{16}$ &  $7.0 \times 10^{16}$ &  0.39   \\
\hline
\end{tabular}
\end{table}