对乙酰氨基苯磺酰氟作为氨基酸衍生试剂性能的研究及其在毛细管电泳分离检测氨基酸中的应用

【作者】 汤晓庆；

【导师】 瞿其曙； 胡效亚；

【作者基本信息】 扬州大学 ， 分析化学， 2007， 硕士

【摘要】 一、对乙酰氨基苯磺酰氟的合成及其氨基酸衍生性能的研究采用一种新的方法合成了一种新的紫外衍生试剂——对乙酰氨基苯磺酰氟(PAABS-F)用来标记和测定氨基酸。PAABS-F的摩尔吸光系数为3.00×104 L·mol-1·cm-1 ,是常用紫外衍生试剂的三倍。PAABS-F非常稳定,便宜,无毒,容易在实验室合成并能与一级和二级氨基酸快速反应。反应条件温和,与氨基酸反应后的衍生产物很稳定,检测灵敏度高,且衍生反应产率也很高。在室温无须避光的条件下存放7天也无其他副产物产生。被PAABS-F标记的20种常见氨基酸能在毛细管电泳上成功分离检测。质量检出下限(S/N = 3)为59.3 fmol (色氨酸)- 1.70 pmol (组氨酸)。二、PAABS-F衍生测定酒中的氨基酸建立了一种简单快速的方法分离检测用对乙酰氨基苯磺酰氟(PAABS-F)衍生的20种标准氨基酸。在35°C下,20种标准氨基酸与PAABS-F反应30 min后在毛细管电泳上分离检测。缓冲液为pH 9.3的20 mmol/L的硼酸缓冲液,126 mmol/L十二烷基硫酸钠(SDS),8 mmol/Lβ-环糊精(β-CD)和20 mmol/L NaCl。分离结果表明,在利用毛细管电泳分离阴离子物质时,β-CD是一种有效的添加剂。在最佳分离条件下,20种标准氨基酸在16 min内被成功分离检测。利用这种方法,分离测定了啤酒和黄酒中的氨基酸。三、通过控制电渗流采用胶束电动色谱改进氨基酸的分离研究了Mg2+和三种一价阳离子(Na+,Li+和K+)作为缓冲液添加剂以减少电渗流,从而改进胶束电动色谱分离对乙酰氨基苯磺酰氟(PAABS-F)衍生的20种标准氨基酸。研究发现,随着阳离子浓度的增加,电渗流(EOF)不断减小的顺序为Mg2+>K+>Na+>Li+。综合考虑迁移时间、分离度和峰型等因数,Na+作为缓冲液添加剂是最佳的。采用这种方法,20种标准氨基酸在不到14 min内得到了成功的分离。四、氨基酸的毛细管电泳手性拆分研究以对乙酰氨基苯磺酰氟(PAABS-F)为柱前紫外衍生试剂,利用胶束电动色谱(MEKC),以环糊精(α-环糊精(α-CD)、β-环糊精(β-CD))和脱氧胆酸钠(SDC)作为手性选择剂,通过优化分离过程中的相关参数,实现了10种氨基酸成功的手性分离。更多还原

【Abstract】 1. A new method for the synthesis of p-acetamidobenzenesulfonyl fluoride and its characteristics for labeling amino acids.An ultraviolet (UV) labeling reagent named p-acetamidobenzenesulfonyl fluoride (PAABS-F) was synthesized in our laboratory for labeling and determination of amino acids by capillary electrophoresis (CE) with diode-array detector (DAD). The molar absorptivity of PAABS-F is 3.00×104 L·mol-1·cm-1 which is nearly 3 times bigger than any other UV labeling reagents. PAABS-F is very stable, cheap, synthesized easily, nontoxic, and can react very fast with both primary and secondary amino acids in the facile conditions to give the corresponding derivatives, which exhibits excellent sensitivity, stability and high derivative yield. No by-products were found in amino acid derivatives when they were stored at room temperature under natural daylight for at least 7 days. Amino acids from both standard solution and real samples were successfully reacted with this new UV labeling reagent to form highly UV absorption derivatives. The labeled 20 standard amino acids are effectively separated by CE and detected by DAD. The mass detection limits (S/N = 3) were ranged from 59.3 fmol for L-tryptophan to 1.70 pmol for L-histidine.2. A simple method for the quick separation of amino acids in wines with a new labeling reagent in Capillary ElectrophoresisA simple method has been developed for the quick separation of amino acids with a new ultraviolet (UV) labeling reagent named p-acetamidobenzenesulfonyl fluoride (PAABS-F) by capillary electrophoresis (CE). 20 standard amino acids were successfully labeled with PAABS-F at 35°C for 30 minutes, and consequently separated by CE in a buffer system containing 20 mmol/L borate, 126 mmol/L SDS, 8 mmol/Lβ-CD and 20 mmol/L sodium chlorate. The separation results showed thatβ-CD is an effective additive for CE separation of ionic analytes. Under optimal conditions, 20 amino acid standards were separated in 16 min. Using this established simple method, amino acids in beers and yellow wine were successfully determined.3. Enhanced Micellar electrokinetic capillary chromatographic separation of amino acids through control of electroosmotic flow by the buffer cationThe effect of divalent cation (Mg2+) and 3 monovalent cations ( Na+, Li+ and K+ ) are estimated as buffer additives to reduce electroosmotic flow (EOF) to facilitate the micellar electrokinetic capillary chromatographic (MEKC) separation of p-acetamidobenzenesulfonyl fluoride (PAABS-F) derivatives of 20 standard amino acids. It is found out that as the cation concentration increases EOF decreases and reduction of EOF follows the order Mg2+ >K+>Na+> Li+. Taking migration time, resolution and peak shape of the derivatives into account, it is best for Na+ as the buffer additive though Na+ must be used at a higher concentration than either K+ or Mg2+.4.Chiral separation of D,L-amino acids by capillary electrophoresisA simple method for the chiral separation of amino acid enantiomers using p-acetamidobenzenesulfonyl fluoride (PAABS-F) as precolumn derivation reagent by micellar electrokinetic chromatography (MEKC) with diode array detector at 254 nm has been established. Cyclodextrin (CD) and sodium deoxycholic (SDC) were used as binary chiral selectors. It was found that the optimum molar ratio of CD to SDC is 1:1.75 and the best running buffer is 80 mmol/L borate at pH=9.3. Under these optimal conditions, 10 pairs of amino acid enantiomers were successfully resolved.更多还原