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Analytical Instrumentation 分析仪器行业

Parker's selection of generators includes hydrogen generators for fuel and carrier gases, nitrogen generators for LCMS or GCMS, Zero Air Generators for GC, Purge Gas Generators for FT-IR and a wide variety of other gas generation solutions.

Selecting the most effective source for high purity gases is a critical issue for analytical chemists. Hydrogen Gas and Zero Air are used for gas chromatography with flame ionization detection (GC-FID) and gas chromatography with mass spectrometric detection (GC/MS). Nitrogen is used for high-performance liquid chromatography with mass spectrometric detection (LC/MS). 

High purity gases are also used with other instruments: CO2 free purge gas for Fourier Transform Infrared Spectroscopy (FT-IR), ultra high puriity nitrogen for inductively coupled plasma (ICP) systems, dry air for nuclear resonance spectroscopy (NMR) and hydrocarbon-free combustion gas for TOC analyzers among others.

Parker Balston and domnick hunter offer a wide variety of in-house laboratory gas generators that provide significant safety, convenience and cost advantages when compared to the use of tank gas. Maintaining 100% up time for your instruments is critical; preventative maintenance service, on site repair and extended warranties are available to ensure reliable, hassle-free operation of gas generators from Parker Balston. 

Gas Chromatography (GC)
It is well accepted in the field of gas chromatography that the purity of gases utilized for the operation of the gas chromatograph will affect the accuracy of analyses, consistency of results, detector sensitivity, and column life as well as column performance. As a result, it is important that sources of gas used by the chromatographer meet the demand to achieve higher sensitivities required for drug discovery, proteomics, genomics, environmental analysis, quality control procedures, government regulations, etc. Traditionally, high pressure compressed gas cylinders have been used to provide high purity gases; however, more recently, gas generators have become available as a source of high purity gases.

Parker Balston and domnick hunter Hydrogen Generators provide a source of high purity hydrogen for carrier and fuel gas and Parker Balston and domnic hunter Zero Air Generators provide a source of ultra high purity grade zero air for combustion gas. A Parker Hydrogen Gas Generator is designed to be a hazard-free alternative to high pressure gas cylinders. The generator can be used with any instrumentation requiring high purity hydrogen – anywhere a standard electrical supply is available. Deionized water is all that is required to generate a continuous supply of high purity hydrogen.

A Parker Balston Make Up Gas Generator can provide nitrogen gas and zero grade air to FID detectors on Gas Chromatographs. This system is specifically designed to provide on nitrogen gas or nitrogen and zero air to 5 – 6 FIDs.

Liquid Chromatographic System with Mass Spectrometric Detector (LC/MS)
A liquid chromatographic system with a mass spectrometric detector (LC/MS) requires a supply of nitrogen as the curtain gas. Some models of LC/MS require high purity zero grade air as the source gas, and dry (-40°F/-40°C) dewpoint air as the source exhaust gas. In many facilities, these gases are provided by a series of compressed gas tanks. While the use of gas tanks can meet overall requirements of the system, this approach imposes a number of serious operational, safety, and economic disadvantages. 

A considerably safer, more convenient, and cost-effective method of providing the necessary gases is the use of in house gas generators. Parker Balston offers a single system to generate the assorted gases needed for any LCMS requiring three independent gases. The system is capable of producing pure nitrogen for curtain gas, pure zero grade air as gas 1 / gas 2 source gases, and dry -40°F/-40°C dew point air as source exhaust. 

Parker also offers LCMS Nitrogen generation systems to produce a continuous or on demand supply of LCMS grade nitrogen making it a smart alternative to cylinder gas. Systems are available with and without built in compressors.

Fourier Transform Infrared Spectroscopy (FTIR)
The purpose of providing a dry CO2-free purge to an FTIR spectrometer is twofold. The purge prevents deterioration of the beamsplitter by moisture and also eliminates undesired absorbance by water and carbon dioxide in the background. Consequently, the purge enhances the instrument's reliability by the reduction of the potential need for service and increases the accuracy of analysis and signal to noise ratio through the elimination of inconsistencies in the background levels of water and carbon dioxide.

A Parker Balston FTIR Purge Gas Generator is specifically designed to provide a purified purge and air bearing gas from compressed air. The FTIR Purge Gas Generator supplies carbon dioxide-free air at less than -100°F/-73°C dew point with no suspended impurities larger than 0.01 micron. The Parker Balston Purge Gas Generator completely eliminates the inconvenience and high costs of nitrogen cylinders, dewars, and significantly reduces the costs of operating FTIR instrumentation.

Evaporative Light Scattering Detector
Evaporative light scattering detection (ELSD) is a universal detection technique for HPLC that provides a number of distinct advantages over other commonly used detection methods such as UV-VIS adsorbance, fluorescence, and electrochemical measurements. The technique allows for the trace-level detection of essentially all compounds in the sample and does not require the presence of a chromophoric group for detection (required for electrochemical methods such as coulometry). While other universal techniques for HPSC exist, they provide poor sensitivity and are generally restricted to isocratic elution.

The nebulization stage of ELSD detection requires a supply of clean, dry nitrogen from 98% - 99% purity that is regulated from 65 to 80 psig. In many labs, nitrogen is provided by the evaporation of liquid nitrogen from a liquid dewar, or a high pressure cylinder. The use of an in-house generator to provide nitrogen for ELSD offers significant benefits which include safety, convenience, and cost savings.

A Parker nitrogen generator can produce up to 99.5% pure nitrogen on a continuous basis which is more than satisfactory for ELSD measurements.

Nuclear Magnetic Resonance Spectroscopy
NMR spectroscopy is a powerful analytical technique available for determining the three dimensional solution structure of proteins that form the molecular basis for biological processes. Clean dry air is used routinely in NMR for sample spinning and lifting. However, recent developments in magnet technology have seen a move towards the use of clean dry nitrogen for this purpose at field strengths above 600 MHz to avoid paramagnetic influences of oxygen contained in air. In addition, NMR instruments equipped with a variable temperature probe are subject to freezing if the air contains any water vapor.

Parker Balston and domnick hunter Nitrogen Generators eliminate the need to purchase and store dangerous nitrogen gas tanks. A Parker Balston Ultra Dry Air system will provide air with a dewpoint of -100 degrees F and prevent costly freeze ups. For chemists operating at field strengths above 600 MHz, a Parker Nitrogen Generator will produce up to 467 slpm of compressed nitrogen on site.

Atomic Absorption Spectroscopy
A high proportion of atomic adsorption spectrometers use acetylene as a fuel gas and air as an oxidant gas. It is essential that the air used as oxidant is of the correct cleanliness and purity. Any contaminants in the air such as dirt, oil or water will hasten the speed at which the burner head becomes contaminated naturally leading to increased damage, downtime and service engineer call outs.

A Parker Balston Atomic Absorption Gas Purifier will purify gases used with Atomic Absorption Spectrophotometers. The purifier consists of two independent filtration systems. The first is designed to purify the compressed air (oxidant) and the second purifies the acetylene gas. This system removes liquid acetone and solid particulate from the gas.

Thermal Analysis
A broad range of thermal analysis (TA) techniques measure the effects of temperature stability and other physical properties of polymers that are used in pharmaceuticals and pharmaceutical packaging. When TA measurements are taken, the chemical nature of the polymer should not change because of a reaction with oxygen or water vapor in the sample chamber. To minimize the possibility of oxidation or other reactions, a high purity inert gas, such as nitrogen, is passed through the sample chamber to displace the air.

A high pressure tank, a dewar, or an in house generator can supply nitrogen for thermal analysis. An in house nitrogen generator provides significant benefits compared with other approaches, including increased safety and convenience, lower cost, and diminished use of energy. A Parker Balston Nitrogen Generator can produce up to 61 SLPM of compressed nitrogen on site. The purity level of the nitrogen stream is defined by the user for the application and may range from 95% to 99.5%.

Total Organic Carbon (TOC) Analysis
Total Organic Carbon (TOC) Analyzers are used to measure organic carbon in water. TOC analysis includes three discrete steps: 1) Acidification of the sample to remove inorganic carbonaceous material and purgeable organic carbon (methane). 2) Oxidation of the organic matter in the sample (typically via persulfate in a heated quartz tube) into CO2. 3) Detection of the CO2 (typically by non-dispersive IR).

High purity air, oxygen or Nitrogen is used to carry the CO2 from the oxidation process to the detector, and its purity is a critical issue in the optimization of the sensitivity and operating range of the system. The gas must be free of CO, CO2, and hydrocarbons (i.e. compressor oils), and is typically supplied to the analyzer at a pressure of 80 to 100 psig and at a flow rate of 400 to 800 mL/min to provide a broad operating range. 

Although carrier gas for TOC analysis can be provided by cylinders, many labs employ an in house generator to supply this gas. A Parker Balston TOC Gas Generator can produce carrier/combustion gas from an existing compressed air supply for TOC instruments, eliminating the need to purchase expensive, inconvenient, high pressure cylinder of air, nitrogen or oxygen.