ASTM D8024-16

5.1 TTPC may be used in various industrial and commercial products for use as a biocide. Products containing TTPC have been approved for controlling algal, bacterial, and fungal slimes in industrial water systems.5.2 This method has been used to determine TTPC in reagent water and a river water (Table 8).

1.1 This test method covers the determination of (Tri-n-butyl)-n-tetradecylphosphonium chloride (TTPC) in water by dilution with acetone, filtration and analysis by liquid chromatography/tandem mass spectrometry. This test method is not amenable for the analysis of isomeric mixtures of Tributyl-tetradecylphosphonium chloride. TTPC is a biocide that strongly adsorbs to soils.2 The water samples are prepared in a solution of 75 % acetone and 25 % water because TTPC has an affinity for surfaces and particles. The reporting range for this method is from 100–4000 ng/L. This analyte is qualitatively and quantitatively determined by this method. This test method adheres to multiple reaction monitoring (MRM) mass spectrometry.

1.2 A full collaborative study to meet the requirements of Practice D2777 has not been completed. This test method contains single-operator precision and bias based on single-operator data. Publication of standards that have not been fully validated is done to make the current technology accessible to users of standards, and to solicit additional input from the user community.

1.3 The Method Detection Limit1.3.1 The reporting limit in this test method is the minimum value below which data are documented as non-detects. Analyte detections between the method detection limit and the reporting limit are estimated concentrations and are not reported following this test method. The reporting limit is calculated from the concentration of the Level 1 calibration standard as shown in Table 4 for TTPC after taking into account a 2.5 mL water sample volume and a final diluted sample volume of 10 mL (75 % acetone/25 % water). The final solution volume is 10 mL because a 7.5 mL volume of acetone is added to each 2.5 mL water sample which is shaken and filtered.

1.4 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.