\begin{table}%t4
%\centering
\par
\caption{ Total and ionic chemical abundances, and ionization correction factors  of \sexa\ and \sexb\ PNe,  
computed with  the ICF method. \label{Tab_ion_pn} } 
\begin{tabular}{lllllll} 
\hline\hline\noalign{\smallskip} 
					& SexA-PN 	  & SexB-PN1      & SexB-PN2    & SexB-PN3      & SexB-PN4      & SexB-PN5 \\ 
\noalign{\smallskip} 
\hline 
\noalign{\smallskip} 
He$^+$/H$^+$~$\times$~10$^{2}$		&3.6~$\pm$~1.1	  & 9.8~$\pm$~1.5	  & 9.3~$\pm$~1.5	& 7.4~$\pm$~1.5	&9.4~$\pm$~1.3	&12.8~$\pm$~2.		\\
He$^{++}$/H$^+$~$\times$~10$^{2}$		&4.8~$\pm$~0.5	  & 0.09~$\pm$~0.05 & 0.3~$\pm$~0.1	& 0.2~$\pm$~0.1	&0.1~$\pm$~0.1	&0.5~$\pm$~0.1		\\
\noalign{\smallskip} 
He/H~$\times$~10$^{2}$			&8.4~$\pm$~1.6	  & 9.9~$\pm$~1.5	  & 9.6~$\pm$~1.6	& 7.6~$\pm$~1.6	&0.95~$\pm$~1.4	&13.3~$\pm$~2.1		\\
\hline
\par
\noalign{\smallskip} 
N$^0$/H$^+$~$\times$~10$^{5}$		&3.9~$\pm$~ 1.2 	  & --		  &--		 &--		&--		&--		\\
N$^+$/H$^+$~$\times$~10$^{5}$		&7.1~$\pm$~ 0.9	  & 0.008:	  &0.003:	 &0.03~$\pm$~0.01 &0.015~$\pm$~0.01 &0.04~$\pm$~0.02		\\
ICF(N)					&3.0	  	  & 72.	  	  &19.		 &--		&45.		&130.		\\
\noalign{\smallskip} 
N/H~$\times$~10$^{5}$			&22.~$\pm$~10.	  & 0.5:	  &0.5:		 &$>$0.03	&0.7~$\pm$~0.5	&5.~$\pm$~3.		\\
\hline
\par
\noalign{\smallskip} 
O$^0$/H$^+$~$\times$~10$^{5}$		&5.2~$\pm$~1.1	  & 0.06~$\pm$~0.01 & 0.07~$\pm$~0.01&--		&--		&--		\\
O$^+$/H$^+$~$\times$~10$^{5}$		&4.3~$\pm$~1.6	  & 0.13~$\pm$~0.30 & 0.27~$\pm$~0.30&--		&0.4~$\pm$~0.9	&0.1~$\pm$~0.2		\\
O$^{++}$/H$^+$~$\times$~10$^{5}$		&3.2~$\pm$~0.3	  & 9.4~$\pm$~3.6	  & 4.8~$\pm$~3.5	 &3.4~$\pm$~1.9	&17.3~$\pm$~4.	&15.9~$\pm$~4.		\\
ICF(O)					&1.7	  	  & 1.0	  	  & 1.0	 	 &1.0		&1.0		&1.0		\\
\noalign{\smallskip} 
O/H~$\times$~10$^{5}$			&13.0~$\pm$~3.7	  & 9.6~$\pm$~3.7	  & 5.2~$\pm$~3.9	 &3.5~$\pm$~2.4	&17.8~$\pm$~5.	&16.4~$\pm$~5.		\\
\hline
\par
\noalign{\smallskip} 
Ne$^{++}$/H$^+$~$\times$~10$^{6}$		&9.2~$\pm$~3.1	  &150.~$\pm$~80.	  &55.~$\pm$~30.	 &80.~$\pm$~60.	&30.~$\pm$~10.	&45.~$\pm$~20.		\\
ICF(Ne)					&4.1	  	  &1.0		  &1.1		 &1.0		&1.0		&1.0		\\
\noalign{\smallskip} 
Ne/H~$\times$~10$^{5}$			&0.38~$\pm$~0.20	  &1.6~$\pm$~1.2	  &0.6~$\pm$~0.3	 &0.8~$\pm$~0.6	&3.~$\pm$~1.	&5.~$\pm$~3.		\\
\hline
\par
\noalign{\smallskip} 
S$^+$/H$^+$~$\times$~10$^{7}$		&2.3~$\pm$~0.8	  &--		&--		&--		&--		&--		\\
S$^{++}$/H$^+$~$\times$~10$^{7}$		&3.9~$\pm$~0.8	  &--		&--		&0.8~$\pm$~0.8	&0.9~$\pm$~0.8	&2.5~$\pm$~1.		\\
ICF(S)					&1.1		  &--		&--		&--		&2.5		&3.5		\\
\noalign{\smallskip} 
S/H~$\times$~10$^{7}$			&7.0~$\pm$~1.9	  &--		&--		&$>$0.8	&2.~$\pm$~1.	&9.~$\pm$~3.		\\
\hline
\par
\noalign{\smallskip} 
Ar$^{++}$/H$^+$~$\times$~10$^{8}$		&9.1~$\pm$~8.7	  &--		&--		&19.~$\pm$~10.	&--		&--		\\
Ar$^{+++}$/H$^+$~$\times$~10$^{8}$	&--		  &--		&--		&16.~$\pm$~10.	&--		&--		\\
\par
ICF(Ar)					&1.9	  	  &--		&--		&1.3		&--		&--		\\
\noalign{\smallskip} 
Ar/H~$\times$~10$^{7}$			&1.7~$\pm$~1.7	  &--		&--		&5.~$\pm$~4.	&--		&--		\\
\hline
\end{tabular} 
\end{table}