One of the most common applications of the SPECORD® PLUS series in the field of environmental analysis is the determination of phosphate with a sipper system. The determination of phosphate is a widely used method in the analysis of water and waste water. Due to the discharge of waste waters and the seeping of agricultural fertilizer residues, particularly surface waters may have relatively high phosphate content. A reaction mixture of ammonium molybdate, potassium antimony (IIl) tartrat and ascorbic acid is added to the sample for the quantitative determination of phosphate. Potassium hydrogen phosphate is used as standard solution. The quantitative analysis is performed by the calibration with standard solutions followed by the determination of the concentrations in the samples. In order to keep the effort as low as possible, this routine task is often performed with flow-through cells. These cells require the use of a particular accessory, the sipper system. Part of this system is an adjustable cell holder for the flow cells with a pathlength of 1, 2 or 5 cm, as well as a pump unit which allows the flow.
However, this is just one very common example in water analysis, while the SPECORD® PLUS series provides numerous other fields of application. These include enzymatic determinations in food analysis or in the medical field the determination of bile acids. Bile acids are synthesized in the liver and act as emulsifiers in the digestion of fats. Increased bile acid levels in plasma or serum occur in case of liver diseases such as acute viral hepatitis, liver sclerosis, liver cancer or toxic hepatic damages. Bile acid concentrations are determined enzymatically.
Because of their effect and substance specificity the enzymes enable a number of simultaneous metabolic processes in the human organism. In the routine analysis enzymatic methods are of great importance. By the measurement of the absorbance change in the UV range of absorbent coenzymes nearly all substances which can be converted by enzymes can be determined photometrically.
An enzyme-based analysis is fast and can be performed without time-consuming sample preparation. It is performed under physiological conditions. The reagents are harmless and easy to handle. Furthermore the documentation of individual substances in mixtures is possible. Thanks to an extensive collection of enzymatic methods in the WinASPECT PLUS® software, the determination of the corresponding substance with the relevant measurement setting, sample sequence and evaluation is performed automatically. Furthermore the Peltier-tempered cell changer enables enzymatic analyses of multiple samples which require very exact tempering.
SPECORD® PLUS stands for ease of use and flexibility for uncomplicated and versatile UV/Vis analysis. The monochromator with imaging holographic grating reduces stray light and guarantees absolute precision of the measuring results. The minimized number of movable components ensures highest reliability, a notably improved signal-to-noise ratio and an ideal energy throughput. Real double-beam mode provides highest precision and an improved long-term stability by measurement of sample and reference at the same time. The measurement results always represent the current energetic comparison of the two beams. This allows compensating of drift of the radiation source and extinction changes of the reference sample. The innovative CDD technology (cooled double detection) with two Peltier-tempered detectors ensures accurate measurement values and very good stability. The radiation sources are pre-adjusted and voltage stabilized. An internal holmium oxide filter ensures automatic wavelength calibration and optimized wavelength accuracy and reproducibility. A variable spectral resolution allows the visualization of even smallest details in the spectrum. SPECORD® has been developed for user-friendly operation: Intuitive navigation, a comprehensive collection of methods, the Self Check System and particularly the wide range of accessories make it easy for the user to run analyses.
If routine tasks or special applications – for 50 years the spectrophotometer from Jena has been the instrument of choice for users around the world. This is no surprise, since the constant pursuit of outstanding performance is the unifying element of Carl Zeiss Jena and Analytik Jena AG with their glorious tradition.