Socket.io and offline people in android

I was wondering about something using socket.io and android.

I realized a little chat application between a webpage and an android app. The problem is when I need to chat with the android app when the device doesn't have a network connection.

Is it possible to manage this with socket.io in nodejs ? In fact, I realized that it takes 1-2 mns to node to know that the user lost the connexion.. So the server tries to send but cant. And it's lost.

Do you have an idea ?