Hi Chinyenye,  I agree with ...

Hi Chinyenye,  I agree with Troy Davis that the human taste senses are the most adapt that we know of.  However it is generally thought that the tongue tastes only the basic flavours of sweet, sour, bitter, salty and umami (savoury), while the nose is able to identify far more flavours.  So a odour test by a panel of trained "sniffers" will go a long way without needing to use the mouth.  Some laboratories leave the samples in a warm bath for 24 hours before doing the sell test to encourage volatization of the tastes. However there are methods for determining  toxicity using instruments whereby living creatures (fish or daphnia) are  subjected to samples and their behaviour observed (the canary bird approach).  I think this is what Ajit was saying but his message came out a bit jumbled. With fish their activity will increase with toxicity and this can be monitored remotely in a continuous flow system.  There are some instruments that also measure toxicity chemically.