Articles

Cleaning and disinfection of beer lines. Integration of HACCP in the company’s quality management system

Aleksandr Zaitsev, Delta-CT, s.r.o.

Maintenance of beer lines can be divided into two important stages – cleaning and disinfection, which allows to maintain the proper sanitation and prevent spoilage of beer.

The most important commercial purifiers are acids, bases, complexing agents and surfactants. During the cleaning, the user should follow the recommendations was made by the manufacturers of cleaning agents in order to achieve maximum cleaning effect, completely remove the beer stone, organic and mineral deposits and prevent premature wear of lines due to corrosion. After purifier removing, the line should be rinsed. To be sure in the rinsing quality, it’s recommended to use the test strips pH 0-12 (manufactured by Delta-CT, s.r.o.) to control the residual amounts of alkaline and acidic components of detergents.

The second important step of beer line maintenance is disinfection. The microorganisms constituting the natural microflora in the beer and falling from the environment, may adhere to the inner surface of pipes, forming a biofilm. The aim of disinfection is to reduce the population of viable microorganisms on the surface of beer line as well as prevent the emergence and spread of nutrient-related disease. Disinfectants can be based on quaternary ammonium compounds (QAC), amines, guanidines, aldehydes, oxygen- and chlorine-containing compounds. Disinfectants are potentially harmful to humans and the environment, that’s why it’s so important to comply with all the necessary requirements when dealing with them. An errors in the preparation or storage of disinfectant solutions caused failure to ensure proper disinfection and in some cases may harm service personnel. Monitoring of active substances in solutions of disinfectants is very important that’s why many companies integrate the HACCP (Hazard Analysis and Critical Control Points) in its quality management system. Using the test strips allows you to ensure proper disinfection and eliminate errors in preparation, use and storage of disinfectant solutions.

The test strips, manufactured by Delta-CT, s.r.o., has advantages of rapidity, simplicity and accuracy, and does not require special equipment and highly skilled laboratory technicians. Test strips are made in the form of polymer strips with test pads. Each test pad is a matrix impregnated with sorbents (or solid extractants), chromogens, buffers, stabilizers, wetting and masking agents. Test strips are packaged in boxes and contain instructions for use, as well as a color chart, which shows the concentrations can be determined.

After disinfection, the beer line should be rinsed. It is recommended to check the washings for residual amounts of disinfectant. For these purposes, Delta-CT, s.r.o. was developed the test strips to determine the residual amounts of disinfectants in the rinse water.

Implementation of measures for the maintenance and control of occupational health provides a secure and high-quality products, and create a positive company image.


Errors in pH measurement – significants and limitations

Aleksandr Zaitsev, Delta-CT, s.r.o.

Delta-CT, s.r.o. is a manufacturer and seller of test strips to determine the pH of an aqueous solutions at various intervals of logarithmic scale. Plastic test strips have pads impregnated with a mixture of acid-base indicators. Indicator pads changes colour when immersed in acidic or basic solutions. The coloring of the reaction zone is compared with the color scale to measure pH of the sample.

Delta-CT, s.r.o. test strips are fastest, simplest and low cost tests for pH measuring. Design of test strips comprising a hydrophobic plastic holder allows safety testing of toxic and corrosive solutions.

The user should be aware of possible errors leading to incorrect analysis result. There are five basic errors leading to a false reading in pH measurement.

Acid Base Error

Test pads are made with indicators. Indicators are acids and bases, so when they are added to weakly buffered solutions, they can affect the pH. For pure water the acid value can be an error of more than 1 pH unit. Buffered solutions do not occur acid and alkaline errors.

The Salt Error

pH measurement accuracy depends on the salt concentration in the sample. When the salt concentration about 2 mol/l, a so-called “salt error” caused by the influence of indicators dissociation. The absolute value of this error is less than 0.2 pH units. Under normal conditions where salt values are less than 2 mol/l, pH values are fairly accurate.

“Protein” Effects

The “protein” error occurs as a result of any proteins present that binding the indicator dye. As a rule protein error occurs in pH measurement of the biological fluids. The “protein” error does not exceed 0.2-0.3 pH units in the case of low protein levels.

Temperature Effects

The temperature of the solution being tested can affect the pH measurement results, due to the influence of temperature on the indicator dissociation constant (pKa). Thus, p-nitrophenol at 0°C is pKa = 7.3 and at 50°C is pKa = 6.81.

The Alcohol Error

The Alcohol Error occurs in those solutions containing organic solvents, usually alcohol, in addition to water. Addition of alcohol to the aqueous system results in alteration of the indicators dissociation constants. This causes a shift of the pH ranges in which indicators change its colour. The amount of alcohol error in water-alcohol solutions can be significant. For example, 70 vol. % alcohol solution causes a shift of phenolphthalein in pH by 2.2 units.

All of these errors can result in inaccurate pH readings, however, despite of these limitations, a significant advantage of test strip method for pH measuring is a simple procedure that can be performed with no special equipment.

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New features of test systems as a basis for extending the application of rapid methods for chemical analysis

Aleksandr Zaitsev, Delta-CT, s.r.o.

Rapid tests are used for quick, easy, rapid and inexpensive chemical and biochemical analysis, which can be done in the field without any special equipment or prior experience in chemistry.

Rapid tests allow for qualitative and quantitative on-site analysis. They have been successfully used in industry and agriculture, healthcare facilities, and even at home.

The general principle of rapid tests is based on the color reaction of chromogenic reagents impregnated on various sorbents. Chromogens react to form a visually observable analytical signal (color change in the reaction zone), proportional to the quantity of analyte. The resulting color of the test pad is compared with a color scale, determining the analyte concentration.

A number of technical quality criteria can be defined for the development and manufacture of test strips.

 

Parameter
Characteristic
Sensitivity of the reaction zone
Specifies the minimum detection limit (the lowest concentration of a compound that can be measured)
Clear visualization and resolution of the color scale
These parameters are interrelated and affect the accuracy of the test results
Selectivity of the reaction zone
It characterizes the possibility of detecting an analyte in the presence of other accompanying substances
Analysis speed
Chemical reactions proceed at different rates. It does not affect the accuracy of analysis, but defines the usability
Clear operational documentation
It reduces the risk of user error
Tamper-evident packaging
It allows to avoid unauthorized access to the goods during storage and transtortation
Shelf-life and storage conditions
It provides convenient transport and store of the test strips

 

Currently, there are several manufacturers of rapid tests in the European Union. A lot of research in the field of rapid tests has been done by Delta-CT, s.r.o. In particular, there were created new rapid tests based on the solid extractants which can increase the selectivity, sensitivity and accuracy of analysis. The research in the field of molecular filters allows to eliminate the influence of interfering ions in analytical determinations. The creation of the multi-stage systems comprising a signal recognition, transmission and actuator sites allows us to realize competitive advantages and offer high-quality products.

At the present time, the importance of rapid tests for on-site analysis is growing. There is an increased interest in rapid tests for environmental monitoring, analysis of drinking water, food, pharmaceuticals, biological samples, industrial solutions and wastewater. Rapid tests constitute an inexpensive way to determine substances without trained personnel.