https://www.selleckchem.com/ All results indicated that the determination of Hg using improved LCGD with the addition of chemical modifiers has high sensitivity, low LOD, well precision and low power consumption. Water samples containing high mercury (10-20 mg L-1) and low mercury (0.2-5 mg L-1) can be determined by improved LCGD-AES with no chemical modifier and 4% methanol, respectively. Adding 4% methanol significantly reduces the matrix effects from real water samples. The measurement results of spiked samples using LCGD-AES are largely consistent with the spiked value. In addition, the recoveries of Hg are ranged from 95.7% to 114.8%, suggesting that the measurement results of Hg by LCGD-AES are accurate and reliable. Overall, the improved LCGD-AES with adding chemical modifiers is a promising technique for on-site and real-time monitoring of Hg in water samples because of its portability, lower cost and speed.Breath analysis offers a promising method of noninvasive analyses of volatile metabolites and xenobiotics present in human body. Isoprene is one of the highest abundant volatile organic compounds (VOCs) present in human exhaled breath. Breath isoprene (50-200 part per billion by volume (ppbv) or higher) can be analyzed by using mass spectroscopy-based methods, yet laser absorption spectral detection of breath isoprene has not been much reported, partially due to its ultraviolet (UV) absorption wavelength and the spectral overlap with other breath VOCs such as acetone in the same wavelength region. These facts make it challenging to develop a spectroscopy-based breath isoprene analyzer for a potential portable instrument. Here we report on the development of a cavity ringdown spectroscopy (CRDS) system for detection of breath isoprene in the UV region near 226 nm. First, we investigated spectral absorption interferences near 226 nm and selected an optimal detection wavelength at 226.56 nm with minimum to no spectral interference. We then measured absorptio