Besides {HEAD ~ the formation} of layers, the separation of {TAIL ~ the sample} can also be detected using the pH value and temperature 
Besides { HEAD ~ the formation } of layers , the separation of { TAIL ~ the sample } can also be detected using the pH value and temperature
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH