Xie Xiaofeng, Tolley Luke T, Truong Thy X, Tolley H Dennis, Farnsworth Paul B, Lee Milton L
Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
Tranxend LLC, 6550 South Millrock Drive, Suite 200, Salt Lake City, UT 84121, USA.
J Chromatogr A. 2017 Nov 10;1523:242-247. doi: 10.1016/j.chroma.2017.07.097. Epub 2017 Aug 1.
The design of a miniaturized LED-based UV-absorption detector was significantly improved for on-column nanoflow LC. The detector measures approximately 27mm×24mm×10mm and weighs only 30g. Detection limits down to the nanomolar range and linearity across 3 orders of magnitude were obtained using sodium anthraquinone-2-sulfonate as a test analyte. Using two miniaturized detectors, a dual-detector system was assembled containing 255nm and 275nm LEDs with only 216nL volume between the detectors A 100μm slit was used for on-column detection with a 150μm i.d. packed capillary column. Chromatographic separation of a phenol mixture was demonstrated using the dual-detector system, with each detector producing a unique chromatogram. Less than 6% variation in the ratios of absorbances measured at the two wavelengths for specific analytes was obtained across 3 orders of magnitude concentration, which demonstrates the potential of using absorption ratio measurements for target analyte detection. The dual-detector system was used for simple, but accurate, mobile phase flow rate measurement at the exit of the column. With a flow rate range from 200 to 2000nL/min, less than 3% variation was observed.
基于LED的微型紫外吸收检测器的设计针对柱上纳流液相色谱进行了显著改进。该检测器尺寸约为27mm×24mm×10mm，重量仅30g。以蒽醌-2-磺酸钠作为测试分析物，检测限低至纳摩尔范围，线性范围跨越3个数量级。使用两个微型检测器，组装了一个双检测器系统，该系统包含255nm和275nm的LED，两个检测器之间的体积仅为216nL。使用内径150μm的填充毛细管柱进行柱上检测时，采用了100μm的狭缝。使用双检测器系统展示了酚类混合物的色谱分离，每个检测器都产生了独特的色谱图。在3个数量级的浓度范围内，特定分析物在两个波长处测得的吸光度比值变化小于6%，这证明了使用吸光度比值测量进行目标分析物检测的潜力。双检测器系统用于在柱出口处进行简单但准确的流动相流速测量。在200至2000nL/min的流速范围内，观察到的变化小于3%。
