Analyzer technology helps prevent ice formation in liquefied natural gas (LNG) liquefaction. In the LNG liquefaction process, it is desirable to extend the life between regeneration of the mole sieve or to monitor performance of a glycol or amine contactor while avoiding contamination to the natural gas. This is done by checking the output of the bed or column in order to determine the breakthrough point, which indicates that the desiccant is saturated. The unit employs tunable-diode-laser (TDL) spectroscopy to provide accurate and instantaneous measurements of trace amounts of gases such as water or carbon dioxide. The TDL-based gas detection method is not susceptible to aging effects, making its factory calibration a constant.