Office of Ground Water and Drinking Water December 1, 2013

MEMORANDUM

SUBJECT: Basis for Expedited Approval of Methods from ASTM International

FROM: Glynda A. Smith , Chemist

Technical Support Center

TO: The Record

This memo documents th e reviews that were conducted on new versions of methods issued by ASTM International. It provides the background information on why EPA is approving these methods using the expedited method approval process. Each method is discussed individually below:

ASTM International Method D 3223

- 12: ASTM Method D 3223

- 02 was used as the basis for comparison, because it is currently promulgated in the drinking water regulations at 40 CFR 141.23(k)(1) for the analysis of mercury in water. The following changes we re made in the updated version:

 Section 1.4 has been added to specify that SI units are the standard and no other units of measurement are used in this method

.

 The Apparatus Section (7.2) adds the allowance for use of direct reading atomic absorption spect rometers.

 The Reagent s Section (8.3) has been amended to allow use of commercially prepared mercury stock standard solutions.

 In the Sampling Section, Note 6 has been added to allow pH adjustment in the laboratory as long as samples are received within 1 4 days. This reduces the hazards of transporting and handling acids in the field. This modification is consistent with the sample handling practice recommended in EPA Method 200.8 which is also approved for determination of mercury in water. Section 8.3 of EPA Method 200.8 states: “ Preservation may be done at the time of collection, however, to avoid the hazards of strong acids in the field, transport restrictions, and possible contamination it is recommended that the samples be returned to the laborator y within two weeks of collection and acid preserved upon receipt in the laboratory.”

 In the Procedure Section, Note 8 has been added to a llow the use of block digestion systems in place of requiring digestion of samples in a water bath.

 Add subsection 14.2 .4 to the Quality Control Section recommending analysis of continuing calibration blank and continuing calibration verification QC samples.

ASTM Method D 3223

- 12 is identical to the promulgated method with respect to sample preparation, analytical procedu re and calculation of mercury concentrations in water samples.2

The precision and bias are unchanged. Therefore, ASTM Method 3223

- 12 is equally as effective as ASTM Method D 3223

- 02 for determining mercury in water.

ASTM International Method D 512

- 12 B ASTM Method D 512

- 04 B was approved for the determination of chloride ion in drinking water in the expedited methods approval action that was published June 3, 2008 (73 FR 31616). In the June 2008 action, ASTM Method D 512

- 04 B was compared against the
ap proved version, ASTM Method D 512

- 89 (reapproved 1999) B, which is cited in the drinking water regulations at 40 CFR 143.4(b). Compare the most recent update, ASTM Method D 512

- 12 B, to the approved version, noting the minor revisions associated with the expedited version

. The changes include :

 Section 1.3 has been added to specify that SI units are the standard and no other units of measurement are used in the method.

 Three documents (ASTM Guide D 5810, ASTM Practice D 5847, ASTM Practice E 200) were adde d to the Reference Section.

 Section 4 (Significance and Use) has been modified to indicate that chloride ion is under regulation in waste water as opposed to water, in general. This is a n acceptable revision

, since chloride ion is a secondary contaminant with a federally unenforceable MCL in drinking water.

 Water purity was changed from Type II to Type I in Section 5.2.

 Reference to ASTM Practice E 200 was corrected in Section 18.2.

 Standard silver nitrate solution concentration in Section 18.4 has been mo dified to list molarity (mole/L) as well as normality (equivalent/L).

 Section 30 (Quality Control) was added to describe the types of QC analyses that must be included to verify that the test results obtained using the method are valid and accurate.

The t wo methods are identical in respect to sample collection/handling protocols, sample preparation, titration procedure and calculation of chloride ion concentration in the sample. The precision and bias are unchanged. Therefore, ASTM Method D 512

- 12 B is e qually as effective as ASTM D 512

- 89 (reapproved 1999) B for determining chloride ion concentrations in water.

ASTM International Method D 4327

- 11 ASTM Method D4327

- 03 was used as the basis for comparison, because it is currently promulgated in the drink ing water regulations at 40 CFR 141.23(k)(1) for the analysis of fluoride, nitrate, nitrite, and orthophosphate in water; the method is also cited in the drinking water regulations at 40 CFR 143.4(b) for determining chloride and sulfate in water. The foll owing changes were made in the updated version:

 In Section 1.4 of the Scope, suggestions for lowering detection limits (e.g., increase sample injection loop volume) have been generalized to encompass the use of newer instrumentation, column technology and eluents.

 Section 1.7 has been added approving the use of electrolytically generated eluents, electrolytically regenerated eluents, electrolytic suppression and electrolytic trap columns (used to purify returning eluent in electrolytically regenerated eluen t systems). The basis for this approval are two ATP letters that are attached to ASTM Method D 4327

- 11. The letters establish method equivalency for the use of these techniques to improve reliability and reproducibility and reduce waste.3

 Section 1.8 has been added to specify that SI units are the standard and no other units of measurement are used in the method.

 Section 4.1 has been modified to include the use of electrolytic suppressors which do not require sulfuric acid.

 Section 5, Note 2 has been modif ied to suggest the option of using hydroxide based eluents in place of carbonate eluents if interference in the determination of the early eluting fluoride ion cannot be resolved.

 Section 7.1.5 has been expanded to encompass electrolytic suppressor devices

.

 Section 8.3.1 has been added to describe preparation of hydroxide eluent as an alternative to carbonate based eluent.

 Each stock solution preparation described in Section 8.5 contains the additional option of using commercially available certified stock solutions instead of manual preparation.

 Section 10.1.3 clarifies that elution order in Figure 1 was obtained using carbonate based eluent; if hydroxide eluent is used, the elution order of sulfate and phosphate will be reversed.

 Section 11.2 has been expa nded to discuss options for reducing background, specifically using hydroxide eluent because hydroxide is reduced to water in the suppressor, or using an additional carbonate removal device if carbonate eluent is used

.

ASTM Method D 4327

- 11 is identical t o the promulgated method with respect to sample collection/handling protocols, sample preparation, analytical procedure, calculation of anion concentrations, and required quality control procedures. The precision and bias are unchanged. Therefore, ASTM M ethod D 4327

- 11 is equally as effective as ASTM Method D 4327

- 03 for the determination of fluoride, nitrate, nitrite, orthophosphate, chloride and sulfate in water.