Lalwani Sanjiv, Tutu Edward, Vigh Gyula
Department of Chemistry, Texas A&M University, College Station, TX 77842-3012, USA.
Electrophoresis. 2005 Jun;26(13):2503-10. doi: 10.1002/elps.200500002.
Ampholytes with close pK(a) values (i.e., good carrier ampholytes (CAs)) are needed as buffers in pH-biased isoelectric trapping (IET) separations. The syntheses of two families of such good CAs were reported recently. Members of the family of diamino sulfate ampholytes (first series) had pI values in the 5.7 < pI < 9.0 range. Members of the family of quaternary ammonium dicarboxylic acid ampholytes (second series) had pI values in the pI < 4.3 range. To further characterize the diamino sulfate ampholytes, their effective mobilities were measured by indirect UV-absorbance detection capillary electrophoresis in a series of background electrolytes (BGEs) with different pH values. The pK(a) and limiting ionic mobility values of the CAs were obtained by fitting these mobility values, as a function of the pH and the ionic strength of the BGEs, to the theoretical mobility expression. These diamino sulfates complete the list of CAs suitable for IET separations.
在pH偏向等电聚焦（IET）分离中，需要具有接近pK(a)值的两性电解质（即良好的载体两性电解质（CA））作为缓冲剂。最近报道了两类此类良好CA的合成方法。二氨基硫酸盐两性电解质家族（第一系列）的成员的pI值在5.7 < pI < 9.0范围内。季铵二羧酸两性电解质家族（第二系列）的成员的pI值在pI < 4.3范围内。为了进一步表征二氨基硫酸盐两性电解质，通过间接紫外吸收检测毛细管电泳在一系列不同pH值的背景电解质（BGE）中测量了它们的有效迁移率。通过将这些迁移率值作为BGE的pH值和离子强度的函数，拟合到理论迁移率表达式中，获得了CA的pK(a)和极限离子迁移率值。这些二氨基硫酸盐完善了适用于IET分离的CA列表。
