微波消解同时衍生化GC-MS法测定血浆中脂肪酸的研究

研究了利用微波能对样品进行加热, 以Ｈ２ＳＯ４ － 甲苯－ 甲醇体系作衍生化试剂, 在消化的同时对血浆中的脂肪酸进行衍生化, 然后用ＧＣ－ ＭＳ 法测定血浆中脂肪酸。 对微波功率、微波加热时间、消解及衍生化试剂等条件进行了优化, 测定结果较好。该法整个消化及衍生化过程只需２ ｍｉｎ , 与传统方法相比大大缩短了实验操作时间, 特别适用于大量样品的测定。     

微波消解同时衍生化GC—MS法测定血浆中脂肪酸的研究

研究了利用微波能对样品进行加热,以Ｈ２ＳＯ４－甲苯－甲醇体系作衍生化试剂,在消化的同时对血浆中的脂肪酸进行衍生化,然后用ＧＣ－ＭＳ法测定血浆中脂肪酸。对微波功率、微波加热时间、消解及衍生化试剂等条件进行了优化,测定结果较好。该法整个消化及衍生化过程只需２ｍｉｎ,与传统方法相比大大缩短了实验操作时间,特别适用于大量样品的测定。     

微波消解分光光度法测定污水中的总磷

建立微波消解分光光度法测定污水中总磷的方法。采用微波消解法消解污水．讨论了消解时间和压力对消解效果的影响。测定总磷的线性范围为0～0．4mg/L。用该法测定总磷环境标准样品中的总磷,测定结果与标准值基本一致,测定结果的相对标准偏差为1．65％(n=5)。     

微波消解-分光光度法测定石油焦中的钒

研究了用微波消解分光光度法测定石油焦中的钒。在石油焦样品处理中采用了常规溶样及微波消解两种方法。重点研究了微波消解石油焦样品的方法,详细考察了微波消解时样品的最佳用量、消解压力、功率、时间,建立了最佳微波消解程序。结果表明两种方法测定结果基本吻合。样品测定的RSD小于4、02％,加标回收率均在98．6％～102．7％之间,但微波消解法的溶样速度是常规法的10倍。钒的线性范围为0～8．0g／L。结果表明,微波消解分光光度法测定石油焦中的钒是一种快速、准确且无环境污染的方法。     

微波消解样品-电感耦合等离子体质谱法测定植物灰分中微量元素

应用电感耦合等离子体质谱法(ICP-MS)同时测定植物灰分中21种微量元素和15种稀土元素.用微波消解样品,对微波消解植物灰分样品的条件进行了试验.其优选微波消解条件为:微波压力为2 MPa,消解时间为10 min,以硝酸、盐酸、氢氟酸、高氯酸(体积比为6比2比1比1)的混合酸消解样品,对0.100 0 g植物标准物质(GBW 07603)进行10次平行测定,微量元素测定结果的相对标准偏差(n=10)在0.87%～5.96%之间,稀土元素测定结果的相对标准偏差(n=10)在2.14%～8.00%之间.     

柱上衍生反相高效液相色谱法测定疾藜提取物中痕量铅

提出了微波消解样品,在线衍生测定疾藜提取物中痕量铅的反相高效液相色谱方法.双水杨醛邻苯二胺为衍生剂,用DiamonsilTM C18色谱柱(4.6 mm×150 mm,5um)作为固定相,甲醇-水-衍生剂(64.5:34.0:1.5体积比)为流动相,检测波长为275 nm,柱温30℃.样品中铅在0.10～0.63 ng范围内呈线性,铅的平均回收率为99.5%,相对标准偏差(n=7)为1.8%.     

不同消解方法对火焰原子吸收光谱法测定乳制品中无机元素含量的影响

取鲜奶及酸奶样品分别用3种不同的消解方法(即常规湿法酸消解法、微波加热酸消解法和干法消解法)做预处理。在所得最终的试样溶液中分别用火焰原子吸收光谱法测定其中6种无机元素(即钙、镁、铜、锌、铁及锰)。试验结果表明:采用微波加热酸消解法处理的样品,6种元素的回收率可达94.5%～100.0%高于其他两种方法的回收率最高值,相关测定值的相标准偏差(n=6)在1.9%～4.2%之间。因此,用火焰原子吸收光谱法测定乳制品中无机元素含量时,用微波加热酸消解法处理样品的效果较好。     

微波消解-微波等离子体炬原子发射光谱法测定合金钢中的铜、锰、钼

用微波等离子体炬 (MPT)为激发光源 ,氩气为等离子体工作气体 ,用气动雾化进样 ,研究了微波消解 微波等离子体炬原子发射光谱法 (MPT AES)测定合金钢中铜、锰、钼的方法。考察了微波功率、载气流量、工作气流量、氧屏蔽气流量等实验参数对测定铜、锰、钼的影响。对微波消解合金钢样品的消解条件进行了考察 ,建立了最佳消解程序。测定铜、锰、钼的检出限分别为 3.3、3.7和 42ng mL ,RSD(n =6)分别为 1 7%、2 .4%、3.8% ,并且测得它们的线性范围分别为0 .0 2～ 5 0 μg mL、0 .0 4～ 5 0 μg mL和 0 .2 0～ 5 0 μg mL。     

微波-超声波协同一步提取衍生化-气相色谱-质谱联用快速分析中药材猫爪草中的脂肪酸

建立了一种微波-超声波协同一步提取衍生化、气相色谱-质谱联用快速测定中药材猫爪草中低含量脂肪酸的方法。以总脂肪酸的色谱峰面积为响应指标,采用响应曲面法优化了主要工艺参数,其结果为: 猫爪草粉末5.0 g,正己烷50.0 mL,微波功率500 W,反应温度50 ℃,催化剂用量0.30 g,甲醇用量4.0 mL,提取衍生化时间8 min。以内标法定量各个脂肪酸的含量,一步提取衍生化法获得的总脂肪酸峰面积((3.327±0.023)×107, n=3)和总不饱和脂肪酸含量((13.59±0.30) mg/g, n=3)明显高于传统方法((2.410±0.036)×107(n=3)和(12.05±0.34) mg/g(n=3))。该方法简化了复杂的样品处理过程,缩短了反应时间,降低了分析成本,改善了提取和衍生化效率,尤其是减少了不饱和脂肪酸的氧化和分解。该方法具有简单、快速和实用性的特点,是一种极具应用潜力的中药材中低含量脂肪酸的快速分析方法。     

微波辅助衍生GC-MS测定脂肪酸及校正变换矩阵法用于食用植物油鉴别的研究

建立了微波衍生化GC—MS测定食用植物油中的脂肪酸含量．并采用校正变换矩阵法对食用植物油的成分进行测定的方法。对微波衍生化的实验条件进行了优化．利用建立的校正模型对40个花生油、菜籽油、芝麻油、棉籽油、棕榈油的二元、三元、四元、五元人工合成样品进行了计算预测，所有样品的平均预测误差部小于5％。对8个实际样品进行了测定．其中有3个掺伪样品．所测调和食用油的结果与标签标示结果相符性较好。本方法可用于快速、准确地测定食用油中各成分含量或定性、定量鉴别掺伪成分。     

微波辅助衍生化GC-MS法测定食用油中的脂肪酸

利用微波技术,研究了用ＫＯＨ－甲醇,Ｈ２ＳＯ４－甲醇－甲苯、ＨＣｌ－甲醇等不同体系对食用油中的脂肪酸进行了衍生化,系统地比较了它们的优劣势,以及适合的分析对象,在１ｍｉｎ内完成衍生物生化反应,选用正庚烷代替传统方法的苯＋石油醚作为脂肪酸甲酯蝗提取剂,与传统消解及衍生化方法相比,具有节省溶剂,省时,易于操作等特点。     

Determination of Fatty Acids by High-Performance Liquid Chromatography with Electrochemical Detection Using A Ferrocene Derivatization Reagent

Abstract

New derivatization method using ferrocene reagents has been developed for the determination of fatty acids by high-performance liquid chromatography with electrochemical detection. Condensation of fatty acids with 3-bromoacetyl-1, 1'-dimethyl-ferrocene was effected in the presence of 18-crown-6 and potassium fluoride. The resulting esters showed the satisfactory sensitivity at +0.60 V vs. an Ag/AgCl reference electrode with a detection limit of 0.5 pmole. Also the high selectivity was obtained by using a twin electrode electrochemical detector. The proposed derivatization method was found applicable to the determination of fatty acids in human serum.     

羟肟酸法快速测定食用油主要营养必需脂肪酸

建立了用ＨＰＬＣ简便快速测定食用油主要营养必需脂肪酸的羟肟酸法。样品一步衍生成羟肟酸上机分析,不需分离纯化。线性范围为０．０５～０．６０ｇ／Ｌ,回收率９６．９３％,ＲＳＤ＝１．８０％（ｎ＝４）,日内和日间ＲＳＤ分别为１．２４％和１．６２％（ｎ＝６）。比较１８∶３,１８∶２和１８∶１的甲酯与相应的三脂肪酸甘油酯标准品衍生的标准曲线,发现二者转化率均相差近一倍,回收率实验和样品实测结果亦证实,选取甲酯标准品衍生作标准曲线用于油脂定量是不合理的。     

花生油中游离脂肪酸的HPLC-FLD分析

采用柱前衍生-高效液相色谱荧光检测法(HPLC-FLD)分析了花生油中的游离脂肪酸.用荧光衍生试剂2-(11 H-苯[a]咔唑)乙基对甲苯磺酸酯(BCETS)作为柱前衍生化试剂对11种脂肪酸标准品(9种不饱和脂肪酸和棕榈酸、硬脂酸)进行衍生,经梯度洗脱实现了11种游离脂肪酸BCETS衍生物的完全分离,使用外标法定量,建...     

Rapid analysis of free medium-chain fatty acids and related ethyl esters in beer using SPE and HRGC

A modification of a procedure by Hage [1] is proposed for the gas chromatographic evaluation of the content of free medium-chain fatty acids and related ethyl esters in beer. The method involves extraction of free fatty acids and ethyl esters by SPE using C₁₈ bonded phase columns, derivatization of free fatty acids and related ethyl esters with diazomethane, and GC analysis using an SP-2340 capillary column. The results obtained have shown the method to be rapid and highly reproducible. The technique has been compared with other methods used for determination of free fatty acids.     

Simultaneous separation and sensitive determination of free fatty acids in blood plasma by high-performance liquid chromatography

Fatty acids are separated by reversed-phase high-performance liquid chromatography after derivatization with a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin. Each derivative eluted from a column is successively hydrolysed by mixing it with an alkaline solution, and the produced fluorescence is detected. The derivatives of series of both saturated and unsaturated fatty acids (C6:0--C20:4) are simultaneously separated by a continuous gradient elution method using a methanol-based solvent containing acetonitrile. The quantitative detection of fatty acids is over a range of 5-1000 pmol per derivatization mixture. This method is applicable to the quantitative analysis of free fatty acids in normal human blood samples and blood samples from diabetic patients. Ten microliters of blood plasma are sufficient to carry out the determination. The analytical results show good recovery and good reproducibility. This sensitive method is very useful for the analysis of fatty acids in very low concentrations.     

血清总磷脂脂肪酸组分的固相萃取-气相色谱法分析

以硅胶基质为固定相,建立了固相萃取-气相色谱(SPE-GC)分离检测血清总磷脂中脂肪酸含量的方法。优化了SPE的洗脱方式及甲醇洗脱量,探讨了衍生化步骤的优化条件。该法对磷脂中各脂肪酸组分测定的线性相关系数约为0.999,回收率在80%左右;日内误差小于4.8%,日间误差小于8.9%。用固相萃取柱分离磷脂简单、快速、有效,用气相色谱检测磷脂中脂肪酸组分方法稳定、可靠。     

Fast,sensitive and highly discriminant gas chromatography–mass spectrometry method for profiling analysis of fatty acids in serum

A method for the determination of fatty acids in serum based on GC–MS (micro-SIS detection mode) has been developed and the separation and cis/trans isomers have been identified. A prior two-step extraction/derivatization procedure accelerated by ultrasound allows individual determination of esterified (EFAs) and non-esterified fatty acids (NEFAs), and shortening of the derivatization steps to 5 min for EFAs and 15 min for NEFAs. The total analysis time for 39 fatty acids was 61 min. The minimum LOD and LOQ values were 0.002 and 0.006 μg/ml, respectively. The proposed method was validated for EFAs and NEFAs using two different methods and the results show no statistical differences between the proposed method and those used as reference. The proposed derivatization–extraction methodology is suitable for fatty-acid analysis of human serum, and can be applied to nutritional and epidemiological studies.     

Pr?chromatographische in situ-Derivatisierung von Fetts?uren im Picomol-Bereich

Summary A simple and rapid derivatization method for C24-C6 fatty acids on HPTLC RP-18 phases is described. The prechromatographic reaction with monodansylpiperazine and monodansylcadaverine takes place at the start. Linear calibration curves are obtained after chromatography (e.g. dansyl palmityl piperazide: r=0.9998), which can be employed for quantitative analysis in the lower nanogram range (determination limit <10 ng). All 10 fatty acids can be separated excellently (R usually 1.5). Stepwise and gradient developments are employed (AMD system).This is the first time that in situ derivatization techniques have been employed for fatty acids leading to fluorescent products in the picomole range and a gradient method has been described which also leads to precise separations on RP phases.

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Herrn Prof. Dr. W. Fresenius zu seinem 75. Geburtstag in Dankbarkeit gewidmet