中国油脂
中國油脂
중국유지
China Oils and Fats
2015年
9期
94-97
,共4页
顶空进样%气相色谱%生物柴油%甲醇%二甲苯
頂空進樣%氣相色譜%生物柴油%甲醇%二甲苯
정공진양%기상색보%생물시유%갑순%이갑분
headspace sampling%gas chromatography%biodiesel%methanol%xylene
生物柴油是以C14 ~C24脂肪酸甲酯为主要成分,残留少量单脂肪酸甘油酯、二脂肪酸甘油酯、三脂肪酸甘油酯及其他微量杂质的复杂重组分体系. 为避免上述重组分对分析结果的影响和干扰以及减少样品前处理步骤、提高测试效率,采用顶空气相色谱法同时快速测定生物柴油中微量甲醇与二甲苯含量. 结果表明,在一定的顶空与色谱条件下,46 min内同时完成4 组分(甲醇、对二甲苯、间二甲苯、邻二甲苯)的测试且具有良好的分离效果. 甲醇在0 . 002% ~1 . 038%(质量分数)之间、二甲苯(对二甲苯、间二甲苯、邻二甲苯)在0 . 001% ~0 . 508%(质量分数)之间均呈现良好的线性关系,相关系数R2为0. 999 7. 各组分的最低检出限在0. 001% ~0. 002%(质量分数)之间,相对标准偏差小于5%,加标回收率在98 . 8% ~106 . 7%之间. 定量数据的精密度良好,定量结果准确可靠,是测定生物柴油中甲醇与二甲苯含量的有效方法.
生物柴油是以C14 ~C24脂肪痠甲酯為主要成分,殘留少量單脂肪痠甘油酯、二脂肪痠甘油酯、三脂肪痠甘油酯及其他微量雜質的複雜重組分體繫. 為避免上述重組分對分析結果的影響和榦擾以及減少樣品前處理步驟、提高測試效率,採用頂空氣相色譜法同時快速測定生物柴油中微量甲醇與二甲苯含量. 結果錶明,在一定的頂空與色譜條件下,46 min內同時完成4 組分(甲醇、對二甲苯、間二甲苯、鄰二甲苯)的測試且具有良好的分離效果. 甲醇在0 . 002% ~1 . 038%(質量分數)之間、二甲苯(對二甲苯、間二甲苯、鄰二甲苯)在0 . 001% ~0 . 508%(質量分數)之間均呈現良好的線性關繫,相關繫數R2為0. 999 7. 各組分的最低檢齣限在0. 001% ~0. 002%(質量分數)之間,相對標準偏差小于5%,加標迴收率在98 . 8% ~106 . 7%之間. 定量數據的精密度良好,定量結果準確可靠,是測定生物柴油中甲醇與二甲苯含量的有效方法.
생물시유시이C14 ~C24지방산갑지위주요성분,잔류소량단지방산감유지、이지방산감유지、삼지방산감유지급기타미량잡질적복잡중조분체계. 위피면상술중조분대분석결과적영향화간우이급감소양품전처리보취、제고측시효솔,채용정공기상색보법동시쾌속측정생물시유중미량갑순여이갑분함량. 결과표명,재일정적정공여색보조건하,46 min내동시완성4 조분(갑순、대이갑분、간이갑분、린이갑분)적측시차구유량호적분리효과. 갑순재0 . 002% ~1 . 038%(질량분수)지간、이갑분(대이갑분、간이갑분、린이갑분)재0 . 001% ~0 . 508%(질량분수)지간균정현량호적선성관계,상관계수R2위0. 999 7. 각조분적최저검출한재0. 001% ~0. 002%(질량분수)지간,상대표준편차소우5%,가표회수솔재98 . 8% ~106 . 7%지간. 정량수거적정밀도량호,정량결과준학가고,시측정생물시유중갑순여이갑분함량적유효방법.
Biodiesel is a complex system containing C14 -C24 fatty acid methyl esters as the main ingredi-ents with a bit residues of monoglycerides, diglycerides, triglycerides and other trace impurities. In order to avoid the disturbance of the above heavy components, facilitate the sample pretreatment and improve testing efficiency, the headspace gas chromatography was used to simultaneously determine the contents of methanol and xylenes in biodiesel quickly. The results showed that under proper headspace sampling and chromatographic conditions, the four components ( methanol, para-xylene, meta-xylene, ortho-xy-lene) were well separated in 46 min. It presented excellent linear relationships for methanol in the range of 0. 002% -1. 038% (mass fraction) and xylenes (para-xylene, meta-xylene and ortho-xylene) in the range of 0. 001% -0. 508% (mass fraction). The correlation coefficient R2 was 0. 999 7. The lowest limit of detection of each component was in the range of 0. 001% -0. 002% (mass fraction);moreover, the relative standard deviations were less than 5% and the standard addition recoveries were in the range of 98. 8% -106. 7%. Thus, a reliable method for determining the contents of methanol and xylene in biodiesel was established with good precision and repetition.