ASTM D7266 : 13

Standard Test Method for Analysis of Cyclohexane by Gas Chromatography (External Standard)

Standard Details

1.1 This test method covers the determination of the purity of cyclohexane by gas chromatography. Calibration of the gas chromatography system is done by the external standard calibration technique.

1.2 This test method has been found applicable to the measurement of impurities such as those found in Table 1, which are impurities that may be found in cyclohexane. The impurities can be analyzed over a range of 3 to 200 mg/kg by this method, but may be applicable to a wider range.

TABLE 1 Impurities Known or Suggested to be Present in Commercial Cyclohexane

C₄

(1) n-butane

(2) isobutene

C₅

(3) n-pentane

(4) isopentane

(5) cyclopentane

C₆

(6) n-hexane

(7) 2-methylpentane

(8) 3-methylpentane

(9) methylcyclopentane

(10) benzene

(11) cyclohexene

(12) 2,2-dimethylbutane

(13) 2,3-dimethylbutane

C₇

(14) 3,3-dimethylpentane

(15) 2,2-dimethylpentane

(16) 2,3-dimethylpentane

(17) 2,4-dimethylpentane

(18) 1,1-dimethylcyclopentane

(19) trans-1,3-dimethylcyclopentane

(20) trans-1,2-dimethylcyclopentane

(21) cis-1,2-dimethylcyclopentane

(22) 2,2-dimethylcyclopentane

(23) 2,4-dimethylcyclopentane

(24) cis-1,3-dimethylcyclopentane

(25) ethylcyclopentane

(26) methylcyclohexane

(27) 3-ethylpentane

(28) 3-methylhexane

(29) 2-methylhexane

(30) n-heptane

(31) toluene

C₈

(32) iso-octane

(33) p-xylene

C₉

(34) isopropylcylohexane

1.3 The limit of detection is 1 mg/kg.

1.4 In determining the conformance of the test results using this test method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.

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

1.6 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. For specific hazard statements, see Section 7.