de Frutos-Lezaun, M Determination of phosphate concentration and pH in artificial tear drops. [electronic resource] - Archivos de la Sociedad Espanola de Oftalmologia Aug 2016 - 372-8 p. digital Publication Type: Comparative Study; Journal Article ISSN: 1989-7286 Standard No.: 10.1016/j.oftal.2016.01.018 doi Subjects--Topical Terms: BuffersDrugs, Generic--chemistryHumansHyaluronic Acid--analysisHydrogen-Ion ConcentrationHypromellose Derivatives--analysisLubricant Eye Drops--chemistryPhosphates--analysisPovidone--analysisPreservatives, Pharmaceutical--analysisSpainSpectrophotometry, Ultraviolet