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ASTM D7881-2019 用带反向电压模式的毛细管电泳测定精对苯二甲酸中对甲酰基苯甲酸和对甲苯甲酸的试验方法 Standard Test Method for Determination of 4-Carboxybenzaldehyde and p-Toluic Acid in Purified Terephthalic Acid by Capillary Electrophoresis with Reverse Voltage Mode
<div class="SectionLevel2"> <p class="subsec1 cdone2"><span class="Head3 cdone">1.1</span> This test method<span style="font-style:normal;"><span class="footnote-link">2</span></span> covers the determination of 4-carboxybenzaldehyde (4-CBA) and <span style="font-style:italic;font-weight:normal;" class="overriddenformat">p</span>-toluic acid (<span style="font-style:italic;font-weight:normal;" class="overriddenformat">p</span>-TOL) in purified terephthalic acid (PTA) by capillary electrophoresis (CE) with reverse voltage mode and UV detection. It is applicable for 4-CBA from 3 to 400 mg/kg and for <span style="font-style:italic;font-weight:normal;" class="overriddenformat">p</span>-TOL from 8 to 400 mg/kg, respectively.</p></div> <div class="SectionLevel2"> <p class="subsec1 cdone2"><span class="Head3 cdone">1.2</span> In determining the conformance of the test results using this method to applicable specification, results shall be rounded off in accordance with the rounding-off method of Practice <span class="Body-link1 cdone">E29</span>.</p></div> <div class="SectionLevel2"> <p class="subsec1 cdone2"><span class="Head3 cdone">1.3</span> The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.</p></div> <div class="SectionLevel2"> <p class="caveat cdone2"><span class="Head3 cdone">1.4</span> <i>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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.</i></p></div> <div class="SectionLevel2"> <p class="WTOcaveat cdone2"><span class="Head3 cdone">1.5</span> <i>This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Develo...
2023-09-07 20:12:01浏览:24
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聚乙二醇修饰牛血清白蛋白的反应与分析
采用N,N′-羰基二咪唑活化法活化单甲氧基聚乙二醇5000分子一端的羟基,对活化后的单甲氧基聚乙二醇分子进行了元素分析.用该活化产物对牛血清白蛋白的赖氨酸侧链氨基进行化学修饰.应用毛细管电泳对聚乙二醇修饰后的产物进行了分析,并与高效液相色谱分析结果作了对照研究,表明毛细管电泳对修饰后的牛血清白蛋白有更好的分析效果....
2020-07-10 14:39:05浏览:50
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