Malt intended for use in beer brewing or elsewhere in the food industry
After boiling for two hours on a reflux condenser, the wort is clarified using membrane filtration. The color is measured with a spectrophotometer.
Suitable for analysis of all (laboratory) wort samples
Atomic emission spectroscopy, also known as optical emission spectroscopy, in conjunction with inductively coupled plasma (ICP-AES or ICP-OES) is a technique used to determine and measure elements based on the phenomenon of atomic emission. The solutions to be analyzed are nebulized and the resulting aerosol is transported with the help of a carrier gas into an inductively coupled plasma (ICP). There, the elements are excited to a higher energy state, causing emissions. The spectrometer separates these emissions into individual wavelengths, and the intensities of the spectral lines of the element are measured with detectors (photomultipliers). A qualitative measurement is possible by calibrating the instrument with reference solutions, whereby a linear relationship exists over a broad range (generally several orders of magnitude) between the intensities of the emission lines (spectra) and the concentrations of the elements.
This method describes how to determine the potassium content of water using atomic emission spectrometry.
This method describes how to determine the iron content of water using atomic emission spectrometry.
Refer to W-000.17.210 - Calcium in Wasser, Bestimmung mittels ICP-OES (Principle)
The method describes how to determine the manganese content of water by atomic emission spectrometry.
Refer to W-000.17.210 Calcium in Water, Determination Using Atomic Emission Spectrometry (ICP-AES) (Principle)
Determination of dissolved oxygen concentration using electrochemical oxygen sensors with an optochemical sensor
The basis for these O2 measurements is the detection of photoluminescence produced by an oxygen-sensitive layer. The change in photoluminescence depends on the partial pressure of the oxygen. Given the values for the partial pressure of the oxygen and the temperature, the amount of oxygen gas dissolved in the liquid can be calculated. The oxygen sensor determines the O2 content of the liquid by means of optical detection through a photoluminescent process, in which an oxygen-sensitive layer is exposed to blue light. In doing so, the molecules in this layer become excited and reach a higher energy state. In the absence of oxygen, the molecules emit a red-colored light. If oxygen is present, it collides with the molecules in the oxygen-sensitive layer. The molecules in the oxygen-sensitive layer, which have collided with oxygen, cease to emit light (refer to figure 1). For this reason, a relationship exists between the oxygen concentration and the intensity of the emitted light as well as the intensity and the rapidity with which the intensity of the light diminishes. The intensity of the light is reduced at higher oxygen concentrations, although the rate at which it does so increases. The temperature of the product and the time interval between the light signal and the emission of light (phase shift) are both measured and used to calculate the oxygen content.
The device’s construction enables the state of the blue LED to be monitored using a photodiode. Another photodiode – with a red filter – measures the oxygen-dependent red light (refer to figure 2). This light is emitted by the luminophores due to photoluminescence (fluorescence) after they reach an excited state through exposure to the blue light. As a result of this exposure, the electrons of the luminophores are elevated to a higher energy level. As they return to their original energy level, they emit a red light.