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:

Instrument database: Jasco Inc. - PU-2089 quaternary low pressure gradient pump
Instrument database: Shimadzu Europe - Nexera series LC-40
Rapid automated arsenic speciation analysis by inductively coupled plasma mass spectrometry | EVISA's News
Instrument database: Bischoff Analysentechnik und -geräte GmbH - HPLC Compact Pump 2250
Instrument database: Prince Technologies B.V. - PrinCE-C 650 and 660 Capillary Electrophoresis Systems
Instrument database: Tecan - Power Washer 384
Instrument database: CETAC Technologies - CEI-100 Capillary Electrophoresis Interface for ICP-MS
Ultra-sensitive speciation analysis of inorganic platinum-chloride complexes in platinum-based drugs by HPLC-ICP-MS | EVISA's News
Instrument database: Jasco Inc. - PU-2080 Isocratic HPLC pump
Instrument database: Agilent Technologies Inc. - G1600 Capillary Electrophoresis System
The Determination of Hexavalent Chromium in Airborne Particulate Matter in Presence of High Amounts of Trivalent Chromium | EVISA's News
Link database: EPA-ORD: Method 218.6: Hexavalent Chromium in Water by Ion Chromatography
Instrument database: Prince Technologies B.V. - PrinCE 250 and PrinCE-C 255 Capillary Electrophoresis System
Instrument database: Gilson, Inc - GX-271 ASPEC™ SolidPhase Extraction system
Material database: Sigma-Aldrich - Auxiliary reagent for AAS: Cesium chloride Lanthanum chloride
Arsenic Speciation in Rice Cereals for Infants | EVISA's News
All about Chromatography - Resources related to Chromatography | EVISA's News
Instrument database: SPEX CertiPrep - 2000 Geno/Grinder
Instrument database: Bio-Rad Laboratories - QuadTec UV/vis Detector
Company database: Exaxol Corporation