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1.1 This test method covers the determination by gas chromatography of propylene glycol monomethyl ether (PM), dipropylene glycol monomethyl ether (DPM), and propylene glycol monomethyl ether acetate (PMA).
Dipropylene glycol monomethyl ether (DPM) is a mixture of four isomers: 1-(2-methoxy-1-methylethoxy)-2-propanol is one of the major isomers.
Propylene glycol monomethyl ether acetate (PMA) is a mixture of two isomers: 1-methoxy-2-acetoxypropane and 2-methoxy-1-acetoxypropane.
1.1.2 This test method covers the determination of DPM in the range from 98 to 100 %, PM in the range from 0.05 to 0.3 %, and tripropylene glycol monomethyl ether (TPM) in the range from 0.06 to 0.3 %.
1.3 The following applies to all specified limits in this standard; for purposes of determining conformance with this standard, an observed value or a calculated value shall be rounded off “to the nearest unit” in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E29.
|Engelse titel||Standard Test Method for Purity of Propylene Glycol Monomethyl Ether, Dipropylene Glycol Monomethyl Ether, and Propylene Glycol Monomethyl Ether Acetate|