Abstract: The invention features an optical medium for calibrating UV absorbance detectors, methods for making such an optical medium, and methods for calibrating UV absorbance detectors using such a medium. The optical calibration medium includes a gel-sol silica glass monolith with a rare-earth dopant therein. The rare-earth dopant exhibits at least one spectral feature in at least the far UV range. The constituents of the gel-sol silica glass monolith are selected so the rare-earth doped sol-gel glass monolith exhibits a transmittance in the far UV range so each distinct spectral feature of the rare-earth dopant in the far UV range is discernable. The transmittance in a particular embodiment is at least about 50% at about 250 nm. The rare earth materials selected for use as dopants are those exhibiting a wide range of spectral features, preferably over a range from about 190 nm to about 700 nm and more particularly exhibit at least one distinct spectral feature in the range from about 190 nm to about 300 nm.

Abstract: A capillary column comprising monodispersed particles. The capillary is formed using a suitable substrate, wherein two plates are bonded together. At least one of the plates comprises a channel where particle beads are housed. Particle bead positions are of defined and equivalent diameter are arranged along the longitudinal axis of the housing structure. These positions are used to position packing material used to occupy the column. The particle beads themselves are of equivalent diameter.

Abstract: A photometric measurement flow cell having measurement path-lengths that can be adjusted down to less than 0.1 mm. The measurement path-length is controlled by both a common flow cell body and the dimensional parameters of a stepped sealing optical element. The stepped optical element includes a stem portion that can be made in various lengths to create a family flow cell measurement path-lengths. The replacement of one stepped element with another having a different stem length within the flow cell creates a reliable method to adjust the measured path-length of the flow cell.

Abstract: An improved method and apparatus for identifying peaks and for determining the boundaries of those peaks, and boundaries of multiple peaks and shoulders within chromatograms. The method and apparatus effects real time identification and determination of the boundaries of these peaks for the purpose of fraction collection. The method and apparatus determines the boundary of a peak within a detector response profile that comprises data points plotted graphically on an X and Y-axis wherein the X-axis represents a first variable and the Y-axis represents a second variable, each variable having a value. The plot at each of the data points has a slope. Data points having a slope which deviates from a consistent value define a peak, and data points having a slope with a consistent value define a baseline.

Abstract: An optical scheme that substantially eliminates spherical aberration and coma, thereby substantially improving fluorescence excitation and collection efficiency. The optical scheme utilizes a laser beam focused by an optical component through the curved surface of a hyper-hemisphere. The hyper-hemisphere focuses the beam sharply at a known point while avoiding spherical aberration and coma. The optical scheme includes both a hyper-hemisphere and a hemisphere. Both the hyper-hemisphere and hemisphere have a substantially planar surface. The substantially planar surface of the hyper-hemisphere is optimally located so that a capillary or cell can be positioned at an internal aplanatic radius. This results in an aplanatic focus at the capillary or cell such that the spherical aberration and coma are zero. A single hyper-hemisphere having a substantially planar surface can be used, wherein the capillary is located at an aplanatic point on the substantially planar surface of the single hyper-hemisphere.

Abstract: A LC column cartridge comprising a memory component integrally attached to it at the time of its manufacture, as well as a method for producing such a LC column cartridge with an integral memory component is disclosed. The memory component is a semiconductor memory chip. The amount of data stored will depend upon the memory capacity of the component, and how the data is recovered will depend on whether or not a microcontroller is incorporated in the component itself. Components could be read only or read/write or be partitioned with a read only area for manufacturing information and a read/write area for usage data. The information stored could vary from the minimal amount of data required to identify the column and its quality control test performance in text format to a full quality control trace and usage history.

Abstract: A modular flow cell having a high optical throughput, a long optical path length and a small cross-section. The modular flow cell configuration includes remote ports or connections for liquid and light input, and liquid and light output. The flow cell includes a flow cell body having two ends, each with a respective end interface secured thereto. The flow cell is configured to formn a part of a modular flow cell assembly. The flow cell body includes a channel having a through-aperture with an inner surface. A light guiding material, e.g. a transparent fluoropolymer material having a refractive index less than the refractive index of common chromatography solvents, is disposed proximate to the channel to form a light guiding through-aperture in the flow cell body.

Abstract: A chromatographic flow cell having the capacity to handle fluid flow from one or more chromatographic systems, at widely varying flow rates without the need to change flow cells or detectors. The flow cell itself acts as a tee where two or more fluidic inlet lines intersect with a common inlet channel. The common inlet channel is configured so that the diameter and length minimizes the total volume, unswept volume, bandspreading, and backpressure. The common outlet channel, inlet lines and the outlet line are sized to provide for adequate fluidic handling at the varied flow rates.

Abstract: The invention features an optical medium for calibrating UV absorbance detectors, methods for making such an optical medium, and methods for calibrating UV absorbance detectors using such a medium. The optical calibration medium includes a gel-sol silica glass monolith with a rare-earth dopant therein. The rare-earth dopant exhibits at least one spectral feature in at least the far UV range. The constituents of the gel-sol silica glass monolith are selected so the rare-earth doped sol-gel glass monolith exhibits a transmittance in the far UV range so each distinct spectral feature of the rare-earth dopant in the far UV range is discernable.