An organic light emitting device that improves contrast by forming a gate wiring and a data wiring of a black matrix with a concentration gradient between a conductive material of high transmittance and a conductive material of high reflectivity. The relative purity andor concentration of oil-containing aliquots can be determined by cooling approximately equal volumes of two or more aliquots to a temperature near or below 0 degrees Celsius. A second substrate is bonded to the passviation layer and polished as a thin substrate layer. The rotation of the disk can be selectively controlled to vary a fluid flow rate. Another embodiment places the backpressure restrictor downstream of the gas chromatograph’s measurement element and its carrier pre-heat coil.