Simultaneous determination of 72 veterinary drugs in shrimp by modified QuEChERS and high performance liquid chromatography-tandem mass spectrometry was written by Bu, Ming-nan;Shi, Zhi-hong;Kang, Jian;Fan, Chun-lin;Pang, Guo-fang. And the article was included in Fenxi Ceshi Xuebao in 2012.Application In Synthesis of 1-Ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid sesquihydrate This article mentions the following:
A method was developed for the simultaneous determination of 72 veterinary residues in shrimps by QuEChERS and high performance liquid chromatog.-tandem mass spectrometry. The sample was extracted with 5% acetic acid-acetonitrile, and the supernatant liquid was directly purified with C18, meanwhile, acetonitrile was used for the precipitation of protein. The extract was evaporated under nitrogen stream, and redissolved with 1 mL 0.1% formic acid-acetonitrile(4:1). Prior to the injection into LC-MS/MS, the sample was filtered through a 0.22μm filter membrane. The HPLC separation was performed on ZORBAX SB-C18 column by gradient elution with acetonitrile and 0.1%formic acid as mobile phase. The anal. of target compounds was carried out with electrospray ionization(ESI) under multi-reaction monitoring(MRM) mode. The external standard method was used for quantification. Under the optimal conditions, the correlation coefficients for 97.2% of the veterinaries were larger than 0.95 in the linear range of 0.1-1840μg/kg, and the limits of quantitation ranged from 0.02μg/kg to 33.58μg/kg. The recoveries of 72 veterinary at three spiked levels were between 61% and 119%, except that for di-Bu succinate, cefapirin, cefquinome, ceftiofur, lincomycin ane diazinon were between 38% and 58%, and their relative standard deviations were in the range of 1.6%-20%. The established method was used for the screening and determination of real samples(pteris shrimp, freshwater shrimp and sea shrimp) bought from supermarket. It was shown that no residue was detected in the sea shrimp and pteris shrimp samples, and 4.0μg/kg of sulfadiazine as well as 2.2μg/kg of sulfamethoxazole were found in freshwater shrimp sample, but the concentrations were all lower than the MRLs. In the experiment, the researchers used many compounds, for example, 1-Ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid sesquihydrate (cas: 84294-96-2Application In Synthesis of 1-Ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid sesquihydrate).
1-Ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid sesquihydrate (cas: 84294-96-2) belongs to naphthyridine derivatives. Functionalized naphthyridines and their benzo/heterofused analogs are present in numerous marine products and reported to possess wide-ranging activities such as antiproliferative, antiaggressive, and HIV-1 integrase inhibition in addition to their use as anti-HCV agents. Imidazonaphthyridines have been prepared through a ‘one-pot’ three-component ‘domino’ reaction between the keto-ester, acrolein, and ethylenediamine in presence of 4 Å molecular sieves. The corresponding thiazolonaphthyridine is obtained from a similar reaction using 2-aminoethanethiol and Dowex basic anion-exchange resin.Application In Synthesis of 1-Ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro-1,8-naphthyridine-3-carboxylic acid sesquihydrate
Referemce:
1,8-Naphthyridine – Wikipedia,
1,8-Naphthyridine | C8H6N2 – PubChem