Question on "sort" command

Hello,

I have some problems with the command sort :
How can I specify the field seperator "\t" on sort command?

I try to sort a file which have a field seperator : a tabulation.
I wrote : cat toto.file | sort -t \t -k 2n > result.txt
but the second field (numeric field) in the result.txt file is not sorted.

I tried some others command line like these:
cat toto.file | sort -t "\t" -k 2n > result.txt
cat toto.file | sort -t"\t" -k 2n > result.txt
cat toto.file | sort -t\t -k 2n > result.txt
cat toto.file | sort -t=\t -k 2n > result.txt
cat toto.file | sort -t="\t" -k 2n > result.txt

But nothing is good.
Do you have a solution please ???

Thanks  a lot for your help.
Robert TITH.