定价： 元 加购物车

定价： 元 加购物车

定价： 元 加购物车

定价： 元 加购物车

1.1 This practice describes the means of estimating the period of time during which a water sample can be stored after collection and preservation without significantly affecting the accuracy of analysis. 1.2 The maximum holding time is highly matrix-dependent and is also dependent on the specific analyte of interest. Therefore, water samples from a specific source must be tested to determine the period of time that sample integrity is maintained by standard preservation practices. 1.3 In those cases where it is not possible to analyze the sample immediately at the time of collection, this practice does not provide information regarding degradation of the constituent of interest or changes in matrix that may occur from the time of sample collection to the time of the initial analysis. 1.4 This practice does not provide information regarding holding time for concentration of analyte less than one order of magnitude above the criterion of detection. 1.5 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.

定价： 0元

Separation and identification of stabilizers used in the manufacture of HDPE are necessary in order to correlate performance properties with polymer composition. This test method provides a means of determining BHT, BHEB, Isonox 129, Irganox 1010, and Irganox 1076 levels in HDPE samples. This test method should be applicable for the determination of other antioxidants such as Cyanox 425, Cyanox 1790, Cyanox 2246, Ultranox 236, and Ultranox 246, but the applicability of this test method has not been investigated for these antioxidants. The additive-extraction procedure is made effective by the insolubility of the polymer sample in solvents generally used for liquid chromatographic analysis. The lowest level of detection for a phenolic antioxidant is approximately 2 ppm under optimum conditions. Other procedures that have been used successfully to remove additives from the plastics matrix include thin-film, microwave,10 ultrasonic,11 and supercritical fluid extractions.11 , 12 , 13 Procedures other than HPLC have been used successfully to separate additives, including SFC13 and capillary GC.14 1.1 This test method covers a liquid-chromatographic procedure for the separation of some additives currently used in high-density polyethylene. These additives are extracted with cyclohexane prior to liquid-chromatographic separation. The ultraviolet absorbance (200 nm) of the compound(s) is measured; quantitation is performed using the internal standard method. Note 1—There is no similar or equivalent ISO standard. 1.2 The values stated in SI units are to be regarded as the standard. 1.3 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. Specific precautionary statements are given in Section 9.

定价： 0元

Separation and identification of stabilizers used in the manufacture of linear low-density polyethylene are necessary in order to correlate performance properties with polymer composition. This test method provides a means to determine BHT, BHEB, Isonox 129, erucamide slip, Irganox 1010, and Irganox 1076 levels in linear low-density polyethylene samples. This test method should be applicable for the determination of other antioxidants such as Ultranox 626, Ethanox 330, Santanox R, and Topanol CA, but the applicability of this test method has not been investigated for these antioxidants.The additive extraction procedure is made effective by the insolubility of the polymer sample in solvents generally used for liquid chromatographic analysis.Under optimum conditions, the lowest level of detection for a phenolic antioxidant is approximately 2 ppm.Other methods that have been successfully used to remove additives from the plastics matrix include thin film, microwave, ultrasonic, and supercritical fluid extractions. Other methods have been successfully used to separate additive including SFC and GC.1.1 This test method covers a liquid-chromatographic procedure for the separation of some additives currently used in linear low-density polyethylene. These additives are extracted with either isobutanol or isopropanol prior to liquid-chromatographic separation. The ultraviolet absorbance (200 nm) of the compound(s) is measured; quantitation is performed using the internal standard method.1.2 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. Specific precautionary statements are given in Section 9.Note 1—There is no equivalent ISO standard.

定价： 0元