ASTM D5974-15
采用毛細管氣相色譜法測定妥爾油分餾產品中脂肪和樹脂酸的標準試驗方法
Standard Test Methods for Fatty and Rosin Acids in Tall Oil Fractionation Products by Capillary Gas Chromatography
ASTM D5974-15 發布歷史
ASTM D5974-15由美國材料與試驗協會 US-ASTM 發布于 2015。
ASTM D5974-15在國際標準分類中歸屬于: 67.080.10 水果及其制品,67.200.10 動物和植物的脂肪和油。
ASTM D5974-15 采用毛細管氣相色譜法測定妥爾油分餾產品中脂肪和樹脂酸的標準試驗方法的最新版本是哪一版？
最新版本是 ASTM D5974-20 。
ASTM D5974-15 發布之時，引用了標準
ASTM D5974-15的歷代版本如下：
- 2020年 ASTM D5974-20 通過毛細管氣相色譜法測定妥爾油分餾產物中脂肪和松香酸的標準測試方法
- 2015年 ASTM D5974-15 采用毛細管氣相色譜法測定妥爾油分餾產品中脂肪和樹脂酸的標準試驗方法
- 2000年 ASTM D5974-00(2010) 用毛細管氣相色譜法對妥爾油分級分離產品的脂肪和樹脂酸的標準試驗方法
- 2000年 ASTM D5974-00(2005) 用毛細管氣相色譜法測定妥爾油分級分離產品中脂肪和樹脂酸的標準試驗方法
- 2000年 ASTM D5974-00 通過毛細管氣相色譜法測定妥爾油分餾產物中脂肪和松香酸的標準測試方法
- 2000年 ASTM D5974-96 通過毛細管氣相色譜法測定妥爾油分餾產物中脂肪和松香酸的標準測試方法
3.1 Tall oil fractionated products derived from tall oil are important commercial materials, primarily composed of fatty acids and rosin acids, but also containing some neutral material (see Terminology D804). For many applications, it is necessary to know the level of the individual fatty acids and rosin acids present in these products. Gas chromatography has proven to be a useful tool for such determinations (see Test Methods D509), and capillary chromatography, described in these test methods, is considered to be the most effective gas chromatographic technique currently available. In particular situations, other techniques may be more suitable than gas chromatography. For example, the presence of fatty acid esters in the sample would result in transesterification during the derivatization step that may affect the results.
3.2 Due to hydrogen bonding, unmodified tall oil fatty acids and rosin acids cannot be volatilized at atmospheric pressure without undergoing decomposition. So, it is necessary to convert the free acids to the more volatile and more stable methyl esters, prior to chromatographic separation.
3.3 These test methods describe four ways to prepare methyl esters. The classic method is through the use of diazomethane, but diazomethane is a hazardous and toxic material, and so is no longer the preferred agent. The use of diazomethane is detailed in Appendix X1.
3.3.1 TMAH causes isomerization of a sample’s di- and polyunsaturated fatty acids, when it is used in even a slight excess. This leads to inaccurate results for the individual fatty acid components. TMAH should be used for materials containing only rosin acids, or when the identification or quantitation of individual fatty acid components is not important.
3.3.2 TMPAH is the recommended methylating agent when the identification or quantitation of individual di- and polyunsaturated fatty acids is required. TMPAH produces results that are very similar to those of diazomethane, but without the hazards that are associated with diazomethane. A considerable excess of TMPAH may cause isomerization of conjugated compounds similar to that encountered with TMAH.
3.3.3 DMF-DMA gives results comparable to TMPAH and is easy and safe to use. However, the reagent is moisture sensitive, requiring samples to be free of any significant levels of water.
3.4 Two test methods for calculating the amounts of the individual fatty acid and rosin acid methyl esters are included in these test methods. When the actual weight percentage of a given compound is required, the “internal standard” method must be used. This method involves adding a known amount of an internal standard to a known amount of test material, and comparing the area of the peak associated with the internal standard with the area of the peak of the individual fatty acid or rosin acid methyl esters. The “area percent” method will give the relative amount of each component, by comparing the area of the appropriate peak to the total area of all peaks. Non-eluting compounds will lead to erroneous (absolute) results with this method.
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- 標準號
- ASTM D5974-15
- 發布
- 2015年
- 發布單位
- 美國材料與試驗協會
- 替代標準
- ASTM D5974-20
- 當前最新
- ASTM D5974-20
- 引用標準
- ASTM D509 ASTM D804 ASTM E691