ICP-MS

Most common problems with Al are contamination from external sources and CN polyatomic interference.   Contamination occurs from ceiling tiles so best to use a covered autosampler and highest purity of acids available (Ultrex grade, Seastar, or doubly distilled) which is better than trace metals grade. Use vials pre-cleaned by soaking in 5% HNO3 for several days so that Al is removed.    Make certain to have He at 4.6 or above to remove CN polyatomic interference as best as possible.  Can also reduce the amount of HNO3 to reduce amount of CN formed and thereby get better Al data.  Last, and depending upon customer reporting requirements, perhaps just calibrate from 10 ppb and up.  

Most common problems with Al are contamination from external sources and CN polyatomic interference.   Contamination occurs from ceiling tiles so best to use a covered autosampler and highest purity of acids available (Ultrex grade, Seastar, or doubly distilled) which is better than trace metals grade. Use vials pre-cleaned by soaking in 5% HNO3 for several days so that Al is removed.    Make certain to have He at 4.6 or above to remove CN polyatomic interference as best as possible.  Can also reduce the amount of HNO3 to reduce amount of CN formed and thereby get better Al data.  Last, and depending upon customer reporting requirements, perhaps just calibrate from 10 ppb and up.