A solution that maintains constant  pH by resisting changes in pH from dilution or addition of small amounts of  acids and bases. 

The term "buffer" was found in the following pages:

CE-ICP-MS for speciation analysis | EVISA's News
Instrument database: Teledyne CETAC Technologies - CEI-100 Capillary Electrophoresis Interface for ICP-MS
Instrument database: Prince Technologies B.V. - PrinCE 250 and PrinCE-C 255 Capillary Electrophoresis System
Link database: US EPA Method 1636: Determination of hexavalent chromium by ion chromatography
Instrument database: Alcott Chromatography Inc. - 765 HPLC Pump
Instrument database: SPEX CertiPrep - 2000 Geno/Grinder
All about Chromatography - Resources related to Chromatography | EVISA's News
Material database: Tosoh - Toyopearl AF-Chelate-650
Instrument database: Jasco Inc. - PU-2089 quaternary low pressure gradient pump
Instrument database: Bischoff Analysentechnik und -geräte GmbH - HPLC Compact Pump 2250
Instrument database: Tecan - Columbus Microplate Washer
Company database: Exaxol Corporation
Side effects of cisplatin chemotherpy: Platinum speciation matters | EVISA's News
Instrument database: RECIPE Chemicals + Instruments GmbH - IP3000 Isocratic HPLC Pump
Instrument database: Jasco Inc. - PU-2080 Isocratic HPLC pump
Material database: Sigma-Aldrich - Auxiliary reagent for AAS: Cesium chloride Lanthanum chloride
Instrument database: Waters Corporation - 3100 Mass Detector
Instrument database: Carl Zeiss AG - LIBRA 120
Instrument database: Bio-Rad Laboratories - QuadTec UV/vis Detector
Link database: EPA-ORD: Method 218.6: Hexavalent Chromium in Water by Ion Chromatography