UV-absorbance detector for HPLC based on a light-emitting diode.

A flow-through optical absorption detector for HPLC was constructed using a novel deep-UV light-emitting diode as radiation source with a peak emission wavelength of 255 nm. For measuring the transmitted intensity (a property correlated to Transmittance) a special UV-sensitive photodiode was employed. Besides the power source, no optical or electronic components other than an inexpensive operational amplifier and a few passive components were necessary. The performance of the detector was tested with three substances, namely nitrobenzene, benzoic acid and methyl benzoate, which were separated by gradient elution using an acetonitrile/water mixture and tetrabutylammonium hydrogensulfate as pH-buffer. Calibration curves for concentrations between 1.6 microg.mL(-1) and 400 microg.mL(-1) (nitrobenzene) and 8 microg.mL(-1) and 2.5 mg.mL(-1) (benzoic acid and methyl benzoate) were determined and coefficients of determination, r(2), of 0.9945, 0.9972 and 0.9996 were obtained for quadratic curve fits for the 3 compounds respectively. Relative standard deviations (n = 7) for peak areas were determined as 0.35% (nitrobenzene, 80 microg.mL(-1)), 0.27% (benzoic acid, 400 microg.mL(-1)) and 0.83% (methyl benzoate, 200 microg.mL(-1)). The lower limits of detection were found to be 750 ng.mL(-1), 5.8 microg.mL(-1) and 12 microg.mL(-1) for nitrobenzene, benzoic acid and methyl benzoate respectively.

[1]  Dermot Diamond,et al.  Novel integrated paired emitter-detector diode (PEDD) as a miniaturized photometric detector in HPLC. , 2006, The Analyst.

[2]  Ingo Klimant,et al.  Microsecond lifetime-based optical carbon dioxide sensor using luminescence resonance energy transfer , 1999 .

[3]  Suminda Hapuarachchi,et al.  Capillary electrophoresis with a UV light‐emitting diode source for chemical monitoring of native and derivatized fluorescent compounds , 2006, Electrophoresis.

[4]  K. Lau,et al.  Low pressure ion chromatography with a low cost paired emitter-detector diode based detector for the determination of alkaline earth metals in water samples. , 2006, Analytica chimica acta.

[5]  M. Macka,et al.  Linearity evaluation in absorbance detection: The use of light‐emitting diodes for on‐capillary detection in capillary electrophoresis , 1996, Electrophoresis.

[6]  Cameron Johns,et al.  Design and performance of a light‐emitting diode detector compatible with a commercial capillary electrophoresis instrument , 2004, Electrophoresis.

[7]  M. Macka,et al.  Performance of a simple UV LED light source in the capillary electrophoresis of inorganic anions with indirect detection using a chromate background electrolyte. , 2002, The Analyst.

[8]  Jianzhong Li,et al.  Light emitting diode-based detectors: Absorbance, fluorescence and spectroelectrochemical measurements in a planar flow-through cell , 2003 .

[9]  H. Flaschka,et al.  Light Emitting Diodes and Phototransistors in Photometric Modules , 1973 .

[10]  R. Scott,et al.  Simple and sensitive ion chromatograph for trace metal determination , 1984 .

[11]  P. Dasgupta,et al.  An affordable high-performance optical absorbance detector for capillary systems , 1997 .

[12]  J. Winefordner,et al.  Sensitive, indirect photometric detector for high-performance liquid chromatography using a light-emitting diode. , 1990, Journal of chromatography.

[13]  P. Worsfold,et al.  Solid-state photometric detectors for flow injection analysis , 1988 .

[14]  P. Hauser,et al.  All-solid-state instrument for fluorescence-based fibre-optic chemical sensors , 1993 .

[15]  Peter C. Hauser,et al.  Capillary Electrophoresis Detector Using a Light Emitting Diode and Optical Fibres , 1997 .

[16]  E. Loree,et al.  Light emitting diode based flow-through optical absorption detectors. , 1993, Talanta.

[17]  M. Trojanowicz,et al.  Simultaneous flow-injection determination of aluminium and zinc using LED photometric detection , 1990 .

[18]  D. Betteridge,et al.  A highly sensitive flow-through phototransducer for unsegmented continuous-flow analysis demonstrating high-speed spectrophotometry at the parts per 109 level and a new method of refractometric determinations , 1978 .

[19]  M. Breadmore,et al.  Separation of Nile Blue‐labelled fatty acids by CE with absorbance detection using a red light‐emitting diode , 2007, Electrophoresis.