Automatic methods

Therefore an automatic method, which means an objective and reproducible process, is necessary to determine the threshold value. The results of this investigations show that the threshold value can be determined reproducible in the point of intersection of two normal distributed frequency approximations. 

Automatic Methods with the help of appropriate algorithms permit the calculation of the threshold to segment ultrasonic images. It is this work, this method has been adopted. 

Physical, chemical, and biological properties are related to the 3D structure of a molecule. In essence, the experimental sources of 3D structure information are X-ray crystallography, electron diffraction, or NMR spectroscopy. For compounds without experimental data on their 3D structure, automatic methods for the conversion of the connectivity information into a 3D model are required (see Section 2.9 of this Textbook and Part 2, Chapter 7.1 of the Handbook) [16]. 

A variety of methods have been developed by mathematicians and computer scientists to address this task, which has become known as data mining (see Chapter 9, Section 9.8). Fayyad defined and described the term data mining as the nontrivial extraction of impHcit, previously unknown and potentially useful information from data, or the search for relationships and global patterns that exist in databases [16]. In order to extract information from huge quantities of data and to gain knowledge from this information, the analysis and exploration have to be performed by automatic or semi-automatic methods. Methods applicable for data analysis are presented in Chapter 9. 

Gleaning Systems. Both manual and automatic methods are used for cleaning food processing (qv) equipment. 

When the number of measurement sets is substantially less than that indicated Fig. 30-25, the interpretation becomes problematic. One option is to use the parameter v ues from one period to describe the measurements from another. If the description is within measurement error, the operation has not changed. If there is a substantial difference between the predictions and the measurements, it is hkely that the operation has changed. Methods such as those developed by Narasimhan et al. (1986) can be used when the number of measurements are large. When implementing automatic methods to treat a large number of measurements, analysts should ensure that the unit is at steady state for each time period. 

MAS Saqi, PA Bates, MJE Sternberg. Towards an automatic method of predicting protein structure by homology An evaluation of suboptimal sequence alignments. Protein Eng 5 305-311, 1992. 

Mettler softening point method — ASTM D 3461-76. This is the most recent method. This automatic method measures the temperature at which the resin flows out of a sample cup under its own weight. The temperature is recorded when the first drop crosses the light path of a photocell (Fig. 21). This method is quite accurate and reproducible. 

Automation of solvent extraction. Although automatic methods of analysis do not fall within the scope of the present text, it is appropriate to emphasise here that solvent extraction methods offer considerable scope for automation. A fully automated solvent extraction procedure, using APDC, for the determination of... 

Five synthetic and five natural colorants were identified and quantified in lyo-philized dairy products and fatty foods using an automatic method based on solid phase extraction using a stationary phase followed by RP-HPLC C,g columns for the sequential retention of colorants and diode array detection. Lyophilization of the samples coupled with the separation procedure provided clean extracts despite the complexity of the food matrices and preserved the sample for at least 2 months without changes in colorant concentrations. The detection limits achieved for the colorants were found in a wide range from 0.03 to 75 pg/g of the lyophilized sample, according to the limits established by the European Union. ... 

Rosenbrock, H.H. An Automatic Method for Finding the Greatest or Least Value of a Function, Computer Journal, Oct. 1960, p. 175. 

Magalhaes LM, Segundo MA, Reis S, Lima JLFC and Rangel AOSS. 2006. Automatic method for the determination of Folin-Ciocalteu reducing capacity in food products. J Agric Food Chem 54(15) 5241-5246. 

Of the methods in common use, the two wet oxidation methods offer the best possibilities for further development. The photo-oxidation method in particular is well suited to automatic analysis. In the version of the total organic carbon method published by Collins and Williams [30] the effluent from the quartz photolysis coil could as easily be diverted to the nitrate analysis unit if inorganic nitrogen were also measured, organic nitrogen could become a routine automatic method. 

Chovan et al.30 described a system that integrates different components of bioanalysis including automatic in vitro incubation, automatic method development (mainly SRM transitions for LC/MS/ MS analysis), and a generic LC method for sample analysis to minimize human intervention and streamline information flow. Automaton software (Applied Biosystems) was used for automatic MS method development. Flow injection was used instead of a HPLC column to decrease run time to 0.8 min per injection. Two injections were performed. The first was performed to locate the precursor ion and optimal declustering potential (DP). The second injection was performed to locate the product ion and optimal collision energy (CE). 

This system is ideal for automatic method for development and gradient optimization. 

Valcarcel, M. and Luque de Castro M.D. (1988) Automatic methods of analysis, Elsevier, Netherlands. 

Microscopic examination permits measurement of the projected area of the particle and also enables an assessment to be made of its two-dimensional shape. In general, the third dimension cannot be determined except when using special stereomicroscopes. The apparent size of particle is compared with that of circles engraved on a graticule in the eyepiece as shown in Figure 1.3. Automatic methods of scanning have been developed. By using the electron microscope 7, the lower limit of size can be reduced to about 0.001 pan. 

Table 2.4 Classification of continuous automatic methods (after Valcarcel and...

Phosphoric acid is used in place of sulphuric acid to avoid the introduction of SO2 into the sample. In practice, the automatic method operates at the rate of 12 samples per hour to avoid inter-sample interaction and a Hnear response is obtained for concentrations between 0 and 1S ppm. Samples with higher levels of SO2 can be analysed after an initial dilution with S02-free water. No attempt was made to provide data-processing facihties for this method. A simple computer program is used to calculate a calibration hne, and, hence, the values of SO2 in the samples. 

Hydrocarbon distillates in the gas oil range ( diesel or derv ) are subject to duty when used as a road fuel. Gas oil, which is often identical to diesel oil in hydrocarbon composition, is exempt from duty when used for stationary machines. In order to prevent its misuse as a road fuel, gas oil is marked with a mixture of 1,4-dfhydroxyanthraquinone (quinizarin), 2-fiirfuraldehyde (furfural) and a red dye. An automatic method for the extraction, identification and determination of quinizarin in gas oil has been used hy the Laboratory of the Government Chemist (LGC) for some years. The presence of furfiiral provides evidence for legal prosecution and the numbers of analyses ordered in the UK merit automatic analysis. 

The TraceCon system is particularly suitable for automatic method development and the screen shown in Fig. 5.12 illustrates this point. 

Fig. 5.12 TraceCon—a simple system for automatic method development.

An economic advantage of automation, which falls outside the scope of Eqs. 1.1 and 1. 2, lies in the potential silent-hours usage of a proven automatic method. Thus, a further two- to threefold increase in throughput for the analysis in question is possible and this is particularly appealing to a laboratory wanting to increase its analytical capacity without increasing its staff numbers. However, if silent-hours working is contemplated, several factors must be carefully evaluated. Safety in operation becomes paramount and the... 

For an automatic method to be preferable purely on economic grounds, its cost must be less than the manual cost by at least an amount equal to the cost of the automatic equipment amortized over a period of three to five years. For many of the more expensive instruments, particularly those in the clinical market, leasing agreements are common and in these cases the annual cost must be less for the automated regime. However, this simple algebraic treatment is very approximate and takes no account of the differences in reagent costs, power requirements, and supervisory cost between the two methods. 

Skeggs, L.T. Jr (1957) Automatic method for colorimetric analysis. American Journal of Clinical Pathology 28, 311-322. 

M. VALCARCEL and M.D. LUQUE DE CASTRO, "Automatic Methods of Analysis", Elsevier, Amsterdam, 1988. 

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