Section 3175.118 - Gas chromatograph requirements(a) All GCs must be installed, operated, and calibrated under GPA 2261-13 (incorporated by reference, see § 3175.30 ).(b) Samples must be analyzed until the un-normalized sum of the mole percent of all gases analyzed is between 97 and 103 percent.(c) A GC may not be used to analyze any sample from an FMP until the verification meets the standards of this paragraph (c).(1) GCs must be verified under GPA 2261-13, Section 6 (incorporated by reference, see § 3175.30 ), not less than once every 7 days.(2) All gases used for verification and calibration must meet the standards of GPA 2198-03, Sections 3 and 4 (incorporated by reference, see § 3175.30 ).(3) All new gases used for verification and calibration must be authenticated prior to verification or calibration under the standards of GPA 2198-03, Section 5 (incorporated by reference, see § 3175.30 ).(4) The gas used to calibrate a GC must be maintained under Section 6 of GPA 2198-03 (incorporated by reference, see § 3175.30 ).(5) If the composition of the gas used for verification as determined by the GC varies from the certified composition of the gas used for verification by more than the reproducibility values listed in GPA 2261-13, Section 10 (incorporated by reference, see § 3175.30 ), the GC must be calibrated under GPA 2261-13, Section 6 (incorporated by reference, see § 3175.30 ).(6) If the GC is calibrated, it must be re-verified under paragraph (c)(5) of this section.(d) The operator must retain documentation of the verifications for the period required under § 3170.6 of this part, and make it available to the BLM upon request. The documentation must include: (1) The components analyzed;(2) The response factor for each component;(3) The peak area for each component;(4) The mole percent of each component as determined by the GC;(5) The mole percent of each component in the gas used for verification;(6) The difference between the mole percents determined in paragraphs (d)(4) and (5) of this section, expressed in relative percent;(7) Evidence that the gas used for verification and calibration:(i) Meets the requirements of paragraph (c)(2) of this section, including a unique identification number of the calibration gas used, the name of the supplier of the calibration gas, and the certified list of the mole percent of each component in the calibration gas;(ii) Was authenticated under paragraph (c)(3) of this section prior to verification or calibration, including the fidelity plots; and(iii) Was maintained under paragraph (c)(4) of this section, including the fidelity plot made as part of the calibration run;(8) The chromatograms generated during the verification process;(9) The time and date the verification was performed; and(10) The name and affiliation of the person performing the verification.(e) Extended analyses must be taken in accordance with GPA 2286-14 (incorporated by reference, see § 3175.30 ) or other method approved by the BLM.