Updated project metadata. Liquid chromatography-mass spectrometry (LC-MS) is a major tool for large scale qualitative and/or quantitative analysis of protein phosphorylation in cells or tissues. Performance of LC is pivotal for the success of phosphoprotemics in both sensitivity and reproducibility. Here we report that the widely used Easy-nLC 1200 has poor performance in analyzing phosphopeptides, particularly in terms of sensitivity and reproducibility, whereas its predecessor, Easy-nLC 1000 has much better performance.