主题：【已应助】求助文献4篇，sciencedirect文献，谢谢！

1、
题目：Simultaneous determination of oxalic, fumaric, maleic and succinic acids in tartaric and malic acids for pharmaceutical use by ion-suppression reversed-phase high performance liquid chromatography  
期刊：Journal of Pharmaceutical and Biomedical Analysis
年卷期：Volume 19, Issues 3-4, 1 March 1999, Pages 621-625
作者：H. Z. Lian, L. Mao, X. L. Ye, J. Miao

2、
题目:Determination of malic acid and other C4 dicarboxylic acids in atmospheric aerosol samples
期刊：Chemosphere
年卷期：Volume 46, Issue 8, March 2002, Pages 1195-1199
作者：Andreas R?hrl, Gerhard Lammel

3
题目：High-performance liquid chromatographic separation and quantification of citric, lactic, malic, oxalic and tartaric acids using a post-column photochemical reaction and chemiluminescence detection
期刊：Journal of Chromatography A,
期刊卷：Volume 1026, Issues 1-2, 13 February 2004, Pages 57-64

4
题目：Determination of citric acid in fermentation media by pyrolysis mass spectrometry
期刊：Journal of Analytical and Applied Pyrolysis
期刊卷：Volume 70, Issue 2, December 2003, Pages 251-261
作者：Alireza Ghassempour, Nahid Mashkouri Najafi, Ali Asghar Amiri