Variable temperature trap

An apparatus responsive to an external presettable control for enabling a precise analysis of organotins in a gas sample by a detector comprising:

• an elongate straight glass tube coupled to receive the gas sample and coupled to the detector for concentrating the organotins therein having a longitudinal chamber containing an absorbent material the straight glass tube is fabricated to withstand temperatures of from -198.degree. C. to 250.degree. C.;
• an elongate sensor probe coaxially extending through the longitudinal chamber and the absorbant material of the elongate straight glass tube for providing an indication of temperature;
• a reservoir of liquid nitrogen suitably shaped to contain the longitudinal chamber of the elongate straight glass tube therein for lowering the temperature of the longitudinal chamber to -198.degree. C. which is below the levels at which organotins are concentrated, the reservoir having a fitting for allowing the selective filling thereof;
• and
• a helically extending coil laterally disposed about the longitudinal chamber of the elongate straight glass tube for heating it to discrete temperatures up to 250.degree. C. in response to temperature indications from the elongate sensor probe at which discrete temperatures the organotins are eluted from the longitudinal chamber to the detector after the organotins have been concentrated from the gas sample in the longitudinal chamber, wherein the elongate sensor probe, the fitting for the reservoir of liquid nitrogen, and the helically extending coil are coupled to the external control.