Kahulugan at paggamit

5.1 It is generally necessary to determine the type and amount of hydrocarbon impurities remaining in the manufacture of toluene, halo halong xylene, paraxylene, o xylene, ethylbenzene, benzene and styrene used as chemical intermediates and solvents. This test method is suitable for setting specifications and as an internal quality control tool for the production or use of these products. Typical impurities are: alkanes containing 1 sa 10 carbon atoms, benzene, toluene, ethylbenzene (EB), xylene, and aromatics containing 9 or more carbon atoms.

5.2 This method may not detect all components, and there may be unknown components that will be assigned inappropriate correction factors, so the results may not be very good.

ASTM D7504-2018 Standard Test Method for Determination of Trace Impurities in Mono-Aromatic Hydrocarbons by Gas Chromatography and Effective Carbon Number

Hakbang 1: Saklaw

1.1 The test method includes the determination of total non-aromatic and monocyclic aromatic hydrocarbons in benzene, toluene, ethylbenzene, p-xylene, o xylene, styrene and mixed xylene by gas chromatography. The purities of benzene, toluene, ethylbenzene, p-xylene, o xylene, styrene and mixed xylene were also calculated. Similar test methods using internal and external standard calibration techniques are test methods D2360, D3797, D4492, D5060, D5135, D5917 and D6563, ayon sa pagkakabanggit.

1.2 For impurities in toluene, halo halong xylene, p-xylene, o xylene, ethylbenzene, benzene and styrene, the limits of detection (LOD) are 0.0002wt % and the limits of quantification (LOQ) are 0.0006wt %.

1.3 When using this method to determine the consistency of test results with applicable specifications, the results should be rounded according to the rounding method of Practice E29.

ASTM D7504-2018 Standard Test Method for Determination of Trace Impurities in Mono-Aromatic Hydrocarbons by Gas Chromatography and Effective Carbon Number

1.4 Ang mga pagpapahalagang ipinahayag sa mga yunit ng SI ay dapat ituring bilang mga pamantayang pagpapahalaga. Walang iba pang mga yunit ng pagsukat ang kasama sa pamantayang ito.

1.5 Ang pamantayang ito ay hindi nilayon upang matugunan ang lahat ng mga alalahanin sa kaligtasan (kung meron man) na nauugnay sa paggamit nito. Responsibilidad ng mga gumagamit ng pamantayang ito na magtatag ng angkop na kaligtasan, mga kasanayan sa kalusugan at kapaligiran at upang matukoy ang pagiging angkop ng mga paghihigpit sa regulasyon bago gamitin.

1.6 Ang internasyonal na pamantayang ito ay batay sa mga internasyonal na kinikilalang pamantayan na mga prinsipyo na itinatag sa “Desisyon sa Mga Prinsipyo para sa Pag unlad ng Internasyonal na Pamantayan, Mga Patnubay at Rekomendasyon” issued by the WTO Committee on Technical Barriers to Trade (TBT).