Spiking procedure

One of the most important trends to simplify these complications is the generation of simple, rapid, and reliable procedures for sample preparation. Method development and setup require the use of materials of known compositions, for example, certified reference materials. Therefore, spiking experiments have to be performed for method quality control. Under such experimental conditions, emphasis has to be placed on the spiking procedures as they exert an influence on the recovery values. Although present scientific knowledge is not perfect, the use of spiking experiments helps to minimize the errors. The integration and automation of all steps between sample preparation... 

Accuracy 2 Recovery, percent Xs+i Xi x 100 Sa Completeness 3a Analytical completeness, percent V X> -j— xlOO 1 xs+i—spiked sample measurement Xi—sample measurement sa—true amount added in the spiking procedure Xi—sample measurement V—number of valid sample measurements T—number of total sample measurements... 

Macedo, C. R., Costa, C. V, Ferreira, J. T., Reynolds, J. H. (1977) Rare-gas dating, III. Evaluation of a double spiking procedure for potassium-argon dating. Earth Planet. Sci. Lett., 34,411-18. 

Glass fibre filters and membrane filters (0 50 mm) were spiked with weighed amounts of an Am or Cs standard solution. The spiking procedure was carried out by immersing the filter in a small volume of the standard solution and evaporation of the solvent. 

The preliminary characterization analysis on the bulk material from river Ruhr revealed also the necessity of a fortification step. However, for these materials, it was decided to opt for a low concentration level (down to around 0.1 pgL-1 per compound) achieved by fortifying the bottled materials just before dispatch of the samples (two days maximum in advance). Due to the chosen spiking procedure, a check of the integrity of the sample received by the laboratories was considered necessary and achieved by a control of the weight of the bottle. Additionally, and once again because of the spiking procedure used, for these materials participants were requested to analyse samples immediately after receipt. 

Cooper AD, Tarbin JA, Farrington WHH, Shearer G, Effects of extraction and spiking procedures on the determination of incurred residues of oxytetracycline in cattle kidney. Food Addit. Contam. A 1998 15(6) 645-650. 

Figure 4.2 Graph showing the increase in moisture absorbed in the same three materials mentioned in Fig. 4.1, during a series of thermal spikes. They were first maintained at 72°C /96% RH (relative humidity) until saturation. They were then periodically removed from that environment, cooled to ambient temperature and then heated rapidly to 135°C, holding the temperature for 5min. This spiking procedure was carried out every week. Each local peak represents one spike. After each spike, the samples were returned to the stated environment [22]...

Application of such a calibration to quantitative analysis of sample extracts requires that these extracts be spiked with the identical quantity Qvis.a of volumetric internal standard as used in the calibration experiments. (It is emphasized that all of these spiking procedures, i.e. calibration solutions plus sample extracts, should be done at the same time, to minimize any drift in the value of Cyis as a result of uncontrolled evaporation.) Then it is straightforward to show that ... 

Fig. 9. Calibration by spiking procedure (standard addition method).

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