Online micro solid phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry for trace analysis of endogenous plant hormones in Ulva linza.

Objective: Ulva linza (L.) is a species of green algae widely distributed in China. We aimed to establish a sensitive online analytical method for quantification of endogenous phytohormones in fresh minute seaweed samples.

A flame photometric detector with a silicon photodiode assembly for sulfur detection.

A flame photometric detector with a silicon photodiode assembly instead of a photomultiplier tube for sulfur detection was developed and evaluated. The photosensitive area of photodiode, the optical design, and band-pass filters, were optimized. It was found that the optimal photosensitive area of the photodiode was 100 (mm), and three focus lenses combined with a broad band-pass filter of 378/52 nm and a QB21 glass yielded the best result.

A novel HPLC flow cell integrated UV light emitting diode induced fluorescence detector as alternative for sensitive determination of aflatoxins.

A novel UV light emitting diode induced fluorescence detector (LED-IF) with HPLC flow cell was designed and evaluated for determination of aflatoxins. Ray tracing method was employed to optimize the design of the optical components (such as reshaping thin lens for light source and fluorescence collection), and optical structure, and the geometry of flow cell. An ordinary UV LED with wavelength of 370 nm and radiant power of 5 mW was used as excitation light source.

A compact and low-cost laser induced fluorescence detector with silicon based photodetector assembly for capillary flow systems.

A compact and low-cost laser induced fluorescence (LIF) detector based on confocal structure for capillary flow systems was developed and applied for analysis of Her2 protein on single Hela cells. A low-power and low-cost 450 nm laser diode (LD) instead of a high quality laser was used as excitation light source. A compact optical design together with shortened optical path length improved the optical efficiency and detection sensitivity.