Abstract: The concentrations of predetermined components of a chemical solution 5 present in a cleaning bath 1 are measured by a measurement unit 11. From the results are calculated the concentrations of various chemical species. From the concentrations calculated and an experimentally obtained rate equation is calculated the treating ability of the chemical solution 5 before supplementation of said components. Then, the treating abilities of chemical solution when the components and ultrapure water are supplemented, are calculated for various cases of amounts supplemented. From these cases is determined a case of amounts supplemented in which the treating ability of chemical solution is maintained at a required level and the amounts supplemented are minimized. Next, the components and ultrapure water are supplemented in respective determined amounts via feeding pumps 21, 23 and 25.

Abstract: In a wet-chemical treatment of a semiconductor substrate with a chemical treatment fluid containing ammonia and hydrogen peroxide, an experiment is carried out in a system where the concentrations of chemical species are known, to experimentally previously determine a relation between an etching rate of an SiO2 film with a mixture of ammonia and hydrogen peroxide and the concentrations of the dissolved chemical species (calculated by a chemical equilibrium analysis) or the temperature of the chemical treatment fluid, and the determined relation is then expressed. The concentrations of the chemical species are calculated by the chemical equilibrium analysis on the basis of values measured by a chemical treatment fluid composition monitor at a suitable interval and values measured by a fluid temperature sensor, and in accordance with the expressed relation, the etching rate of the SiO2 film with the chemical treatment fluid is calculated at the suitable interval.

Abstract: In a denuder (2) serving as a gas collection apparatus, an absorption liquid supply tube (4) for spraying absorption liquid from a nozzle (4a) to the inner wall of a denuder pipe (2a) is provided at the upper portion of the denuder pipe (2a). A sample atmospheric air supply tube (7) for supplying sample atmospheric air into the denuder (2) is provided at the lower portion of the denuder pipe (2a). On the inner wall of the denuder pipe (2a) is formed a photocatalyst thin film layer (13) containing photocatalyst which is optically excited to be made super-hydrophilic upon irradiation of light having specific wavelengths (for example, ultraviolet rays) thereto.

Abstract: Method of pre-treating a sample for metal analysis, the sample including a volatile alkali, by permeating the volatile alkali through a gas permeable membrane, dissolving the volatile alkali in an absorbent, passing ions through a first cation exchange membrane in electrical contact with an anode, reacting the volatile alkali with the ions, and passing the reacted volatile alkali through a second cation exchange membrane in electrical contact with a cathode, whereby the volatile alkali is removed from the sample.

Abstract: The present invention provides a gas analyzer used for contamination control of a clean environment by collecting samples from a plurality of measurement points while switching these points and continuously monitoring the volatile components present in the air of the environment, which analyzer requires no increase in number of parts and can give good response in a short period of measurement; and a gas analysis method using the gas analyzer.The gas analyzer of the present invention has two gas sampling units. Each of solution-feeding pumps 3, 15 is actuated for a different diffusion scrubber. The diffusion scrubber connected to the solution-feeding pump 15 is put in a measurement state; and the to-be-analyzed gas components absorbed by the absorbing solution in the diffusion scrubber are captured by a concentration column 14 and are analyzed by an ion chromatograph 30.

Abstract: A gas component analyzing system having a diffusion scrubber and a chromatograph wherein a flow passage switch valve and a sample injection valve are switched to form a non-circulation flow passage for feeding an absorption liquid into the diffusion scrubber so that absorption liquid captures sample gas components until the sample gas components come into an equilibrium state. Then, both the above valves are switched to form a circulation flow passage for feeding the absorption liquid into a concentration column. Then, both the above valves are further switched to form the non-circulation flow passage to elute the sample gas components for subsequent detection thereof by the chromatograph.

Abstract: In an analytical method for trace amounts of silicic acid in pure water of the present invention, swollen gel which has been swollen with pure water sufficiently is used as granular solid which adsorbs colored silicic acid species. A small amount of swollen gel is aliquotted volumetrically, and then the gel is added to a sample solution. Colored silicic acid species is adsorbed and concentrated on a small amount of the granular solid. Therefore, trace amounts of silicic acid can be determined with high sensitivity.