Update to Tech Memo 2000.06, Elimination of Orthophosphate and Nitrate Analysis by Ion Chromatography. FYI, Update to Tech Memo 2000.06, Elimination of Orthophosphate and Nitrate Analysis by Ion Chromatography. The Laboratory Reporting Levels (LRLs) for Labcode (LC) 1979 (nitrate-plus-nitrite) and LC 1977 (nitrite) were incorrect in Tech Memo 2000.06. The LRLs should be 0.005 mg/L for LC 1979 and 0.001 mg/L for LC 1977. The third paragraph of the Tech Memo should read as follows; Customers who require low-level results for nitrate may still obtain them by requesting LC 1979 (nitrate-plus-nitrite) with an LRL of 0.005 mg/L and LC 1977 (nitrite) with an LRL of 0.001 mg/L, and then calculating the nitrate value. If low-level data are not required, customers are encouraged to use LC 1975 and LC 1973 where LC 1975 has an LRL of 0.05 mg/L. In the case of low-level methods, costs for the replacement labcodes are somewhat higher; however, customers who elect to use labcodes 1975 and 1973 will realize small savings. By grouping the labcodes as suggested the nitrate-plus-nitrite and nitrite will be analyzed simultaneously under identical analytical conditions, thus providing the best nitrate value. An FCC bottle is required for the replacement methods. Attached is the corrected version of Tech Memo 2000.06, please disregard the previous version or make a pen & ink change if you have already downloaded. If there are questions or concerns please contact Gary Cottrell (cottrell@usgs.gov, 303-236-3490). I apologize for any inconvenience caused by this error. Gary Cottrell Attachment