(US4717547-A)      Appts. for scrubbing natural gas free from an undesirable component comprises an absorption column with amine inlet and outlet to produce a flow in contact with the gas, tapping between the inlet and outlet for withdrawing a sample of liq. amine bearing the component, and an optical analyser with a high-pressure high-temp. optical absorption cell communicating with the tapping and emitting a component content signal.    A regulator varies the amine flow rate to the column in response to the detected uptake of component.    The cell pref. comprises two elongate quartz cylinders adjustable to provide a variable spacing between them, this defining an optical trajectory of the cell, with bevelled PTFE joints between cylinders and respective sockets threaded onto cylindrical bodies to permit adjustment.    USE/ADVANTAGE -   Partic. for desulphuration, permits more efficient and safer operation. (6pp)c    (EP188955-B)      Apparatus for adjusting the amine load upon an absorption column, which is used for scrubbing a gas containing acid compounds and in particular H2S with the said amine and comprises a supply pipe for regenerated amine on which are mounted in the direction of the amine flow, a pump and an automatic valve, the said apparatus comprising an amine analyser which is adapted to determine the amount of acid compound in the amine and compare it with a set value and to generate a signal representative of a correction of a reference flow-rate, an addition module receiving a signal representative of a reference flow-rate and the signal from the analyser and producing a signal representative of their sum, and a regulator receiving both the output signal from a flow-rate meter which is arranged on the pipe between the pump and the valve and the signal supplied by the addition module and acting on the valve or the pump, which apparatus being characterised in that the analyser comprises an optical analyser provided with a measuring cell adapted for measuring the absorption of the acid compound present in the amine in the pressure and temperature conditions prevailing in the absorption column and with an adjustable optical path and in that a tapping duct is mounted on the column so as to have one of its ends opening in the liquid phase inside the column and the other end connected to the analyser through a duct. (7pp)