Test kit methods

A considerable number of immunoassay kits for several mycotoxins are now being marketed under various trade names and while most of these kits give satisfactory results when compared with other accepted methods their evaluation can be a source of controversy. Consequently, AOAC Intervention in the USA has established a new Research Institute to test the performance of such proprietary test kit methods (Smith et al., 1994) (Table 11.5). 

Table IV. Analysis of Milk Products with Tri-enzyme Electrode and Boehringer Mannheim (BM) Test-kit Methods...

Sampling and chemical analytical methods (e.g. sensors, passive sampling devices, test kits (see e.g. ISO 17381 2003 Water quality - Selection and application of ready-to-use test kit methods in water analysis ), GC-MS or LC-MS screening methodologies). 

International Standards Organization, 2003c. Water quality - Selection and application of ready-to-use test kit methods in water analysis. ISO 17381 2003. 

Spot tests based on simple kits for quick and inexpensive water testing still find wide application and a number of commercial companies market variations of the test kit methods that are approved by the EPA for Safe Drinking Water Act reporting and recommended for onsite testing. 

Chlorine in Used Petroleum Products (Field Test Kit Method) ... 

P. A. Cunniff, ed.. Official Methods of Analysis of AO AC International, 16th ed., Vols. I and II, AO AC International, Arlington, Va., 1995. Vol. I includes Pesticide Formulations and Pesticide Residues. Over 2100 coUabotatively tested, approved methods for chemical and microbiological analyses, with 149 new methods, 103 revised/updated methods, methods using anibody-based test kits, enzyme immunoassay, and annual supplements containing new and revised methods chemical and common names of all dmgs and pesticides easy-to-locate references. 

G. L. Wheeler, P. F. Lott, and F. W. Yau, MicrochemicalJ. 23, 160—164 (1978). Test kit based on this method available from Hach Chemical Co., Loveland, Colo. 

Bench scale analysis Also known as "bench test . A method of studying different ways of treating wastewater and solids on a small scale in a laboratory. Alken-Murray offers several such test kits including Aiken Clear-Flo Bench Test 1 and Aiken PCB Bench Test. 

The limitations of ELISA methods include the specificity of antibodies, the concentrations of primary antibody and antigen, and the type of reaction solution. Nonspecific binding of either of the antibodies to related antigens, unrelated proteins of other bacteria, or even the microtiter plate may lead to false positive reactions.49,52 57 Use of a monoclonal antibody may decrease crossreactivity with other antigens. For detection of low numbers of bacteria, as in drinking water, the sample may be filtered to concentrate the cells or cultured in a selective broth until it reaches the minimum detection limit for ELISA.49,58 Commercial test kits using dipsticks, immunoblots, and sandwich ELISA methods have been developed for the identification of pathogenic bacteria.58,59... 

A modified method for determining Bayluscide in field trials was described by Strufe [59]. It involved the use of test kit containing safranin granulate and extracting with diethylcarbonate instead of ammonium acetate. The color reaction followed by a Zeiss-Ikon Polytest Colorimeter. 

Several qualitative and quantitative immunochemical methods for CAP analysis in biological matrices of animal origin have been described [101,102, 104,105] (see Table 3). Van de Water et al. [ 102] described an ELISA that detected CAP in swine muscle tissue with an IC50 value of 3 ng mL1. This immunoassay was improved and subsequently optimized incorporating the streptavidin-biotin amplification system. There are also several commercially available test kits (see Table 4). RIDASCREEN is a competitive enzyme immunoassay for the quantitative analysis of CAP residues in milk, eggs, and meat in a microtiter plate. The measurement is made photometrically, obtaining a LOD of 100 ng L 1 in meat and eggs and 150 ng L 1 in milk. The test has been also applied to the analysis of tetracyclines. 

If we try to refine the adequacy between the measurement procedures and the practical needs for wastewater quality monitoring, different metrological (analytical) characteristics have to be considered, such as detection limit, reliability and robustness (Table 3). Even if it is very difficult to compare the analytical methods carried out in the laboratory with on-site measurements (with on-line or tests kits), this presentation points out the main features of the measurement required for different needs. These characteristics define the quality of the available information [3], which constitutes one of the major problems that... 

Ruider and Spatzierer [57] described a simple method for the rapid estimation of nitrogen and phosphorus. They discuss the usefulness of test kits for ammonia nitrogen, nitrate nitrogen and phosphorus. 

Hermann (2000) described a rapid automated method involving generation of a known amount of free radicals and the detection of the excess by photochemiluminescence. Test kits are available for determination of total water-soluble antioxidants, fat-soluble antioxidants and ascorbic acid. A luminometric method was developed for the determination of antioxidative activity and was subsequently applied to anthocyanin and betalaine colour concentrates (Kuchta et al., 1999). The method involved quantification of the interruption in luminescence from the hydrogen peroxide-horse radish peroxidase-luminol system in the presence of antioxidants. 

A variety of miscellaneous elements can also occur in a residual fuel oil fraction. For example, chlorine is present as a chlorinated hydrocarbon and can be determined (ASTM D808, D1317, D6160). A rapid test method suitable for analysis of samples by nontechnical personnel is also available (ASTM D5384) and uses a commercial test kit where the oil sample is reacted with metallic sodium to convert organic halogens to halide, which is titrated with mercuric nitrate using diphenyl carbazone indicator. Iodides and bromides are reported as chloride. 

T. J. Novak (United States Dept, of the Army U, ed.), Microspot test methods and field test kit for on-site inspections of chemical agents. US patent 5935862. 19990810. 

Screening tests for PBG are based on its reaction with DMAB (modified Ehrlichs reaction ). We recommend the trace PBG test kit available from Thermo Electron (UK), which isolates PBG from urine by ion-exchange resin before the reaction with DMAB. Older screening methods, such as those of Schwartz or Hoesch, give false-positive results due to the reaction of DMAB with urea, which is abundant in urine. 

Gentner, P. R. and Haasemen, A. 1979. Method for the determination of cholesterol in milk samples by application of a commercially available enzymatic test kit. Milch-wisseasch 34, 344-346. 

This method is by far the most widely used around the world and generally relies on the direct analytical determination of a key inhibitor component species, such as C1O4, Zn, Mo, PO4, SiC>3, or phosphonate. The degree of control is a function of the frequency and method of analysis, plus the variability in cooling system operation. If inhibitor and other testing is only carried out infrequently (say every 2 to 3 weeks) and only simple field test kits are employed for all analyses, it is unlikely that good long-term control can be satisfactorily achieved. 

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. 

Polynuclear aromatic hydrocarbons (PAH) are aromatic compounds that contain two or more benzene rings fused together. These substances may be analyzed by HPLC, GC, GC/MS and enzyme immunoassay techniques. The latter is a rapid screening method that may be applied for a qualitative or semiquanti-tative determination Test kits are commercially available for such screening. U.S. EPA (1995) has specified a method (Draft Method 4035) that detects a range of PAHs to different degrees and measures the composite of individual responses to determine the total PAHs in the sample. 

PCBs in soils and wastewaters can be rapidly screened on site or in the laboratory by immunoassay technique (Chapter 1.13). Immunoassay test kits are now commercially available from many suppliers. The samples can be tested at the calibration levels of 1 to 50 ppm. The kit primarily contains antibody-coated test tubes or magnetic particles, assay diluent, PCB-enzyme conjugate, a color-forming substance, and a solution to quench the reaction. The method does not distinguish accurately one Aroclor from another. PCBs can be measured semiquantitatively by comparing the optical density of the color formed in the sample against a set of calibration standards using a spectrophotometer. 

In addition to test kits used in EPA-approved screening methods, a variety of other test kits are available from several manufacturers, for example, immunoassay test kits for BTEX in soil and water and for chlorinated solvents in water colorimetric kits for the detection of lead kits for a wide range of water quality parameter manufactured by Hach Company. 

The concept of measurement traceability provides probably the most important strategy to achieve standardisation in laboratory medicine aimed at comparable measurement results regardless of the method, the measurement procedure (test kit) and of the laboratory where the analyses are carried out. 

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