Method performance terms accuracy

In order that the soHds robotic system could be vaHdated fully, each separate step or component of the procedure was isolated and the results verified gravimetrically. The vahdated results showed that the TS, TSS, and TDS-ROE robotic methods performed excellently in terms of precision, accuracy, and method detection Hmit (MDL). These results were found to be equivalent to, or better than, results obtained by manual... 

With the label-free methods in the repertoire of quantitative proteomics practitioners, there is still a need for label-assisted methods to perform quantitation with improved accuracy and precision. Label-assisted methods incorporate stable isotope labels into internal standards (IS) for quantitation this MS-based quantitation method is termed stable isotope dilution. The incorporation of stable isotope labels can be achieved either with or without... 

The split-amplitude strategy represents the total amplitudes as the sum of an a priori known approximate value, obtained from some external source, and an unknown correcting term. Assuming, further, that the known amplitudes represent a good approximation to the true ones, the unknown corrections can be obtained to a high degree of accuracy from a set of linear equations. The results of this article show that when a proper reference space is used, the connected clusters obtained from the MR CISD wave function represent indeed a very good approximation, and the almost linear versions of the RMR CCSD method performs very well. 

Method performance in air analysis involves terms such as accuracy, storage stability, capacity, sampling rate, recovery, and sensitivity. To evaluate the performance of a developed method, certified reference materials for particulate matter, such as urban dust SRM 1649a particulate matter from NIST (Gaithersburg, MD, USA) can be purchased. In addition, a standard reference material has been recently developed for the determination of organic compounds in house dust the SRM 2585 is intended for using in method validation for the analysis of PAHs, PCBs, chlorinated pesticides, and PBDEs (Poster et al. 2007). 

During crop gathering, some parts of Solanaceae plants may be occasionally included. A method for the simultaneous determination of tropine, atropine, scopolamine, homatropine, anisodamine, a-solanine, and a-chaconine in grains and seeds (wheat, rye, maize, soybean, linseed) has been reported by Jandric et al. [84]. The analytes were separated by isocratic HPLC on a Chirobiotic V column and detected by ESl-MS/MS detector operating in the MRM mode. The method performances were presented in terms of linearity in the range 5-80 ng g, specificity, selectivity, accuracy (recoveries from 61 % to 111 %), precision (CV <5 %), and ruggedness. The limits of quantitation (LOQ) were in the range 2.2-4.9 ng g . ... 

Option (Valid) presents a graph of relative standard deviation (c.o.v.) versus concentration, with the relative residuals superimposed. This gives a clear overview of the performance to be expected from a linear calibration Signal = A + B Concentration, both in terms of (relative) precision and of accuracy, because only a well-behaved analytical method will show most of the residuals to be inside a narrow trumpet -like curve this trumpet is wide at low concentrations and should narrow down to c.o.v. = 5% and rel. CL = 10%, or thereabouts, at medium to high concentrations. Residuals that are not randomly distributed about the horizontal axis point either to the presence of outliers, nonlinearity, or errors in the preparation of standards. 

The versatility of the DSC method and the high speed of the experiments have costs in terms of accuracy. For example, the best accuracy in the determination of heat capacities of solids by DSC is typically 1% [3,248-250], at least one order of magnitude worse than the accuracy of the corresponding measurements by adiabatic calorimetry [251]. This accuracy loss may, however, be acceptable for many purposes, because DSC experiments are much faster and require much smaller samples than adiabatic calorimetry experiments. In addition, they can be performed at temperatures significantly above ambient, which are outside the normal operating range of most adiabatic calorimeters. 

Sampling records for any procedure must be complete and should include, but is not restricted to, items relating to the origin of the sample, methods of storage, analytical tests performed, the test methods used, and the analyst(s) who performed the test methods (Table 6.1). In summary, there must be a means to identify the sample history as carefully as possible so that each sample is tracked and defined in terms of source and activity. Thus, the accuracy of the data from any subsequent procedures and tests for which the sample is used will be placed beyond a reasonable doubt. 

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