The Test-Kits

Each column is shipped with a PSS column quality certificate, a column connector, and the test kit, which was used at the PSS quality inspection laboratory to test the column resolution. This allows the user to reproduce the column tests without problems. It should be noted, however, that column test results not only depend on the performance of the column alone, but also on the instrument employed for the test. Figure 9.8 shows an example of a PSS column quality certificate. 

The test kit is used to detect radon in home basements. 

According to the practical equipment there are useful tools, so-called test kits, which are units that contain all the reagents and a simple instrumentation in form of plates, tubes and wells. The test kits work rapidly, are easily to handle and field-portable. Frequently, biochemical principles are applied, especially immunoassay techniques which use body-antibody reactions. 

The quality of the analysis of polynuclear aromatic hydrocarbons is often dependent on the extraction efficiency. Clay and other cohesive soils lower the ability to extract polynuclear aromatic hydrocarbons. Another potential problem with polynuclear aromatic hydrocarbon analysis is that the test kits may have different responses for different compounds. 

DMAB (part of the test kit) is solubilized in 84 ml concentrated acetic acid, with 16 ml perchloric acid added. 

The test kit for the determination of acetic acid released is used according to the manufacturer s protocol (see also below). Spectropho to metric determination of NADH concentration is performed at 340 nm in the milliliter scale, e. g., in an Ultrospec 3000 photometer, and on the microliter scale in a fluorimeter, e. g. FLUOstar. 

The test kit is based on immunoassay techniques and the method takes about 10 minutes to provide an analysis. A unique tag, permanently attached to the polymer, changes the color of special test strips exposed to ppm levels of polymer. The strips indicate the amount of tagged polymer that is present, without interference from other additives and contaminants. This technology is not currently available for continuous inhibitor detection, but given the importance of AH Organic Programs, there is little doubt that further developments will take place. The Water Additives Division of Great Lakes Chemical Corp. have also recently introduced a similar simple and accurate immunoassay test for the detection of Belclene 200 antiscalent. 

Polyclonal antibodies of different types are known to show affinity for specific compounds. Thus, antibodies that can bind to a specific substance to be analyzed are immobilized to the walls of the test tubes, plates, or microwells. Such test tubes and plates are commercially available and supplied in the test kit. A measured amount (between 10 and 50 pL) of sample or sample extract is added to one such test tube containing an assay diluent (a phosphate buffer). An equal volume of analyte-enzyme conjugate (commercially available and supplied in the kit) is then added to the test tube. The enzyme conjugate is a solution containing the same analytes covalently bound to an enzyme. The solution mixture is incubated or allowed to stand for a specific amount of time. During this period, the enzyme conjugate competes with the analyte molecules for a limited number of antibody binding sites in the test tube. 

The spectrophotometer kit used in immunoassay testing is the most expensive part of the test kit hardware. It may be rented from the manufacturer. 

In order to validate the commutability of the DGKC control materials it was necessary to perform split sample measurements with patient samples using the test kit in parallel to the IDMS reference procedure for progesterone. The investigation revealed for both the patient sera and the ring trial results a considerable bias in relation to the reference procedure at low progesterone concentrations. (Fig. 7). The reason for the bad performance of the test was obviously a lack of specificity rather than a lack of commutability of the control materials. At even lower progesterone concentrations the bias increased up to 1000%. It should be noted that the kit manufacturer did unfortunately not issue any lower limit of determination for his measurement procedure. 

Fig. 13 YOUDEN diagram obtained after a ring trial for prolactin left evaluation limits for the luminometric measurement using the test kit from manufacturer 44 middle evaluation limits for the luminometric measurement using the test kit from manufacturer 04 right evaluation limits for the fluorimetric measurement using the test kit from manufacturer 04 the respective participants results are emphasised by dark dots...

This holds also for thyroid-stimulating hormone (TSH), where, as demonstrated in Figure 15, at least three different areas of acceptance have to be used depending on the test kits applied. 

The kitchen personnel do not always feel comfortable with the test kits. Therefore, testing oil at a restaurant is a major challenge. 

The number of carbon resources are 96, which is given by the manufacturer of the test kit. 

The Gen-Probe Mycoplasma TC Rapid Detection System (Eurogenetics) employs the principle of nucleic acid hybridization to detect mycoplasma in tissue culture. Using in-solution hybridization of ribosomal RNA it is possible to detect positive samples in 3 h or less. The test kit contains a 3H-labeled DNA probe homologs to mycoplasma or acholeplasma ribosomal RNA. 

The test kit is certified as an AOAC Performance-Tested Kit and carries a li-censed-to-use certification mark, which is granted for 1 year. 

Most EIA use HRP as the marker enzyme. The activity of HRP can be measured photometrically as well as electrochemically. Using the catalase activity of liver tissue, Mascini and Palleschi (1983b) developed a tissue-based electrode for the measurement of hydrogen peroxide and combined the sensor with commercial test kits for digoxin and insulin. The HRP-labeled hormones of the test kit compete with antigen in the sample in a test tube. The bound HRP activity is inversely proportional to the concentration of insulin and digoxine, respectively. 

Cotinine is the major metabolite of nicotine and is useful for the determination of tobacco smoke exposure. In this case, the test is designed to detect exposure to second hand smoke. Active smokers generally have very high levels of cotinine in their body fluids, and subjects exposed to second-hand smoke are expected to show considerably reduced levels of cotinine. To further define the test, saliva is used as the sample. This further complicates testing, as saliva is a complex mixture of mucous-submandibular gland fluids (-75%) and low viscosity-parotid gland fluids (-25%). The test kit will thus need a collection device that reliably delivers the oral fluid sample to the lateral flow test sample loading pad. 

Immunoassay techniques rely upon synthetic antibodies that have been developed to form a complex with petroleum substances. The antibodies in the test kit are immobilised on the walls of a special cell or membrane. Water samples can be added directly, whereas soils are solvent extracted into a suitable water miscible solvent and added to the cell. A known amount of enzyme with an affinity for the antibody is added. After equilibrium is established, the cell is washed to remove any unreacted material. Colour development reagents which react with the enzyme are added. A solution that stops colour development is also added at a specific time, and the optical density is then measured. Samples showing high optical density (colour intensity) contain low concentrations of analytes. Concentration is inversely proportional to optical density. Kits are generally available for, among others, TPH, BTEX and PAH. A correction factor supplied by the manufacturer is used to calculate TPH and this is subject to variation depending on the product type. These tests do not provide information on product type and have limitations dependent upon soil type and homogeneity. Also, field extraction techniques are not as efficient as laboratory-based extraction techniques. 

The ELISA kits are based on the use of selective antibodies raised against specific PAHs, which are attached to a solid matrix support. These are combined with sensitive enzyme reactions (see Section 6.4.4). The kits provide high selectivity and can provide an immediate answer on site, but the disadvantages are that they can be difficult to use in the less than ideal conditions on site and they can only usually give a range of concentrations, e.g. >50, 20-50, 1-20 or <1 mg/kg of total PAHs and mainly rely on a manual rapid cold shake extraction technique which may only extract a small fraction of the PAHs in some samples. In addition, the test kits can prove quite expensive for a screening analysis. 

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