Development and Evaluation of a Light-emitting Diode Induced Fluorescence Detector Based on Light Source Switching
  
View Full Text    Download reader
DOI:
KeyWord:light-emitting diode (LED)  multi-wavelength  fluorescence detector  ochratoxin A  aflatoxin B1  benzo(α)pyrene
  
AuthorInstitution
WANG Feng-lin,ZHOU Xin-ying,WANG Wen-jing,YANG San-dong, TANG Tao,LI Tong 1. Dalian Elite Analytical Instruments Co.,Ltd.,Dalian ,China; 2. Dalian Engineering Research Center of Chromatography,Dalian ,China; 3. Suzhou Institute of Biomedical Engineering and Technology,Chinese Academy of Sciences,Suzhou ,China
Hits: 1086
Download times: 575
Abstract:
      Fluorescence detector has the characteristics of high sensitivity and good selectivity.It is one of the most commonly used detectors in high performance liquid chromatography(HPLC).In this paper,a multi-wavelength light-emitting diode(LED) induced fluorescence detector was developed based on a confocal optical configuration,which could be applied in detection of variety of substances.The motor multiple calibration positioning technique and light source sliding positioning technique were used to achieve the precise positioning of multiple light sources.And a shared emission optical path was used to simplify the instrument structure and reduce the cost of the instrument.The reliability test on the continuous switching of LED light source for 30 000 cycles showed that the target position errors of the laser ranged within ± 0.2 mm,which realized the accuracy and good repeatability of LED light source positioning,solving the problems of traditional fluorescence detector with complex structure and high price,and LED single wavelength induced fluorescence detector with strong specificity and narrow application range.A mobile phase of methanol and a C18 chromatographic column were used to investigate the baselines of three light sources.Results showed that the developed detector,under excitation light sources of 340,365 and 385 nm ,had baseline noises less than 5.0 × 10-4 FU and a drifts less than 5.0 × 10-3 FU/h.Furthermore,mycotoxins and benzo(α)pyrene were used as probes to evaluate the linearity and sensitivity.Meanwhile,acetonitrile-water-acetic acid(96∶102∶2,by volume),methanol-acetonitrile-water (20∶20∶60) and acetonitrile-water(90∶10) were used as mobile phases for the analysis of ochratoxin A,aflatoxin B1 and benzo(α)pyrene,respectively.The excitation wavelengths of the detector were set at 340,365 and 385 nm,respectively.The concentrations of ochratoxin A,aflatoxin B1 and benzo(α)pyrene showed good linearities (r2 ≥ 0.999 9) in the ranges of 1.0-50.0 ng/mL,0.1-20.0 ng/mL and 0.5-20.0 ng/mL,respectively.The limits of detection were 0.06,0.01 and 0.02 ng/mL,respectively.The repeatability of this detector was investigated,and the result showed that the RSDs (n=11) for sample response values of the three light sources were all less than 1.0%.While using the 340 nm light source as the test condition,the basic performance of the detector under vibration,high temperature and low temperature environments did not changed significantly.The tested results of the detector were comparable in terms of baseline noise,drift and sensitivity,compared with those of the commercially available imported general-purpose fluorescence detectors.With the advantages of simple structure,wide wavelength coverage and good performance,the developed detector showed good application prospects in the detection of mycotoxins and benzo(α)pyrene.
Close