Abstract: A method known in prior art for determining the occupation of the surface of a silica glass component with impurities comprises taking a sample, a process in which at least some of the surface of the silica glass component is brought in contact with an acidic desorption solution, and surface impurities that are to be analyzed are accumulated therein and are subjected to an element-specific analysis. The aim of the invention is to create a method which is based on said method, allows the occupation of the surface of silica glass components to be determined accurately and reproducibly, and is suited for determining small amounts of impurities within the order of magnitude of 1010 atoms/cm2 also directly in situ. Said aim is achieved by the fact that taking the sample encompasses contacting the component surface with an acidic desorption solution containing water, nitric acid, and hydrofluoric acid, the nitric acid concentration in the desorption solution amounting to 1.