All sample and skimmer cones, regardless of ICP-MS manufacturer or design serve the same function. They are the differential apertures separating the sample at atmosphere from the mass filter and detector(s) at high vacuum. Though the fundamental dimensions are all essentially the same (sample cone with shallow angle, skimmer cone with acute angle), each manufacturer has designed the cone's critical dimensions to their own unique specifications (orifice diameter, hole depth, material composition, etc.). The actual cone design may vary significantly from one instrument manufacturer to another. The analytical zone, the area most in need of maintenance displays the most significant differences. These differences, together with sample type (ground water, soil digests, sea water, etc) contribute to the rate at which oxides and salts accumulate in and around the cone orifice. They also affect the rate of cone degradation and influence the cleaning methodology. Ultimately, the quality of your data is the best diagnostic tool for determining when to clean or change your cones. However, if you notice significant buildup on the cone(s), which appear to be occluding the cone orifice, cone removal and cleaning is warranted. All instrument manufacturers prescribe a daily routine to evaluate the status of the system prior to an analytical run. These fast and easy tests can also be used to qualitatively evaluate cone condition...... For more download entire guide at right