Traditional methods, for detection

Electrochemical DNA biosensors are based on the use of nucleic acids or analogues as biorecognition element and electrochemical techniques for the transduction of the physical chemical signal. Two aspects are essential in the development of hybridization biosensors, sensitivity and selectivity. Traditional methods for detecting the hybridization event are too slow and require special preparation. Therefore, there is an enormous interest in developing new hybridization biosensors, and the electrochemical represent a very good alternative [108]. 

The traditional methods for detection of illicit drugs are based either on sniffing of vapors emitted from the contraband materials or on swipe samples by which the suspect object (or person) is swabbed with a suitable material (paper, cloth, or a polymer) that is inserted into a heated inlet of the IMS (Figure 14.3, lONSCAN inlet schematic). These sampling methods have been used in several laboratory and operational scenarios, as shown in Section 14.4. 

The traditional method for detection of waterborne microbes is direct plating. Samples may also be filtered either on- or off-line and filters placed directly on the surface of an agar plate. A range of media for the detection of coliforms is available (Table 13.3) and confirmation of thermotolerant E. coli is possible by incubation at 44 C. 

The traditional method for investigating the forces originating in the body of the bolt, which is based on measuring the torque of the nut, can detect only the bolts with a very great lack of body force since tbe friction coefficient worsens with time. 

In this context it is important to note that the detection of this land of alkali cation impurity in ionic liquids is not easy with traditional methods for reaction monitoring in ionic liquid synthesis (such as conventional NMR spectroscopy). More specialized procedures are required to quantify the amount of alkali ions in the ionic liquid or the quantitative ratio of organic cation to anion. Quantitative ion chromatography is probably the most powerful tool for this kind of quality analysis. 

Evaporative LC-FTIR is rapidly gaining industrial acceptance as a useful tool in low-MW additive analysis. HPLC has also been coupled with various element-selective detectors. There is significant demand for speciation information for many elements, and the separation ability of chromatography coupled to ICP-MS offers the analyst a versatile tool for such studies. It is apparent that ICP-MS is increasingly being employed for chromatographic detection. Several modes of GC, SFC, LC and CE have been hyphenated with ICP-MS for improved detection limits compared to other traditional methods of detection such as UV-VIS spectroscopy. Inorganic speciation deserves more attention. 

The on-line extraction technique does not perform as well as traditional methods for the toluene fraction in contrast to the hexane fraction. The later eluting peaks are much more intense for the traditional sampling in all cases. It seems that CO favors the lower molecular weight molecules, even at high densities. On line FTIR detection did not yield any new information for the aromatic fractions. Highly aromatic material does not absorb infrared radiation greatly. In contrast, UV detectors are quite sensitive and yield significant information for aromatic compounds. 

Faraday detection as described in Section 3.1., is the traditional method for recording NQR signals. As discussed earlier, Faraday detection sensitivity is limited by the detector s own thermal noise. The desire for improved detection sensitivity has driven the search for non-traditional methods and lower noise Faraday methods of RF magnetic field detection. In this section, several methods that have been applied to NQR signal detection will be discussed. 

The traditional method for extracting and separating Hg species from organic matrices for electron capture detection (ECD) is well established and commonly known as the Westoo method since 1966-1967 [22, 23]. It is mostly used for the determination of Me-Hg. Most of the protocols used to date are derived from this method and the general scheme can be summarized as follows ... 

In short, the traditional chemical-analytical methods for detecting specific elements or molecules is (despite the application of modern identification detectors) predominantly used in basic research or for detective investigations, but are rarely applied in the day-to-day quality control of down and feather filling materials. 

Traditional methods for the quantitation of catecholamines [norepinephrine (NE) and epinephrine (E)] relied on the production of detectable fluorophores. In the early fluorometric methods, NE and E were oxidized and rearranged under alkaline conditions to... 

Microbial polysaccharides from Xanthomonas campestris, notably xanthan gum for use in food industry, have been studied. Other polysaccharides like dextrans, pullulans, scleroglucan were isolated from several microbial sources. Incorporation of xanthan gum in traditional Indian fermented foods like Idli and Dosa has been investigated in elaborate details. Other products with supplementation of xanthan gum which have been investigated include orange and lemon squash, commercial tomato soup, yogurt preparations with or without CMC. Immunological methods for detection of xanthan gum in... 

This is the traditional method for alkaloid detection although care should be taken as some nonalkaloids such as iridoids and some flavonoids give a positive reaction Alkaloids give a dark orange-to-red coloration. 

The CAM exhibited near-instantaneous response, detection limits of0.006 mg/m and median relative standard deviations of 3.1% for vapor levels of 0.01 to 0.25 mg/m. During continuous monitoring of air near the machine, short-lived and elevated concentrations of isopropanol were detected when alcohol-wetted cloths were used to clean the machine after contamination accumulated on particular surfaces, and four places in the machine were identified as sources where nicotine vapors were released into the ambient air. In only a few hours, the sources of nicotine vapors were identified, and this had eluded efforts with traditional methods for months. 

As with other brewing surfaces, ATP testing is the most common method for detection of microbial activity within the packaging area. Media used for traditional plating tests are also identical to those described for bright beer, with Raka Ray and NBB the most common media used within the UK brewing industry (Paradh et al., 2011). 

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