J&L Laboratories follows the methodologies prescribed in NACE TM0173, “Methods for Determining Quality of Subsurface Injection Water Using Membrane Filters.”  We will provide our customer with a pre-weighed 0.45µm cellulose nitrate filter at 47mm diameter.  After sampling by the customer, we will pass various heated solutions (140°F) through the Millipore, drying and weighing in between steps.  The steps include passing solutions (in respective order) through the Millipore utilizing vacuum filtration:  Water (removes salts), xylene (removes hydrocarbons), 20% w/v acetic acid (removes carbonates), and 15% w/v hydrochloric acid (removes iron compounds).  The remaining solids are considered to be “acid insolubles.”

Customer notes:

Using filters that are not provided by J&L may affect the quality of the analysis.  Supply companies oftentimes will sell substandard membrane filters that degrade when exposed to the acetic acid and hydrochloric acid during the procedure.  In addition, it is best practice to utilize the identical calibrated analytical balance for the procedure that was used to pre-weigh the filters.  Differences in climate, altitude, HVAC, and non-dampened vibrations will adversely affect analytical balance performance.  Reports include the percent and ppm composition of each component as well as the total suspended solids expressed in ppm.