Loss of target compounds

Difficult to set-up and use Loss of target compounds Not very robust High maintenance Not suitable for dirty samples... 

One key issue of a study is to minimize sampling and analytical errors, loss of target compound and other artifacts through the preparation steps. Therefore it is important to check all steps in the method. Preparation of samples collected on filters and sorbents, dust samples, and material samples will be discussed here. In Section 2.6 some analysis techniques that require no or minimal sample preparation will be mentioned briefly. 

Inert carrier proteins, such as bovine serum albumin, are commonly added to the assay media at high concentrations for screening of isolated targets in order to saturate the potential protein binding surfaces and reduce the loss of target proteins due to adsorption onto the surfaces of the containers, such as plates and vials. The added benefit of inert proteins is that they can bind to lipophilic compounds and increase the solubility of insoluble compounds in the assay buffer. The presence and absence of serum protein can cause difference in solubility and cause a discrepancies between the two assays. 

The detection of target compounds in real time would be the ideal tool for the industry to monitor unwanted contaminants and avoid economical losses due to holding processing activities and storage of suspicious batches. Biosensors, among other sensors, have been widely used in the industry for different applications, including the detection of microorganisms and toxins (Baeumner, 2003). 

The TIC trace from the LC-MS analysis of an extracted river water sample, spiked with 3 p.g dm of atrazine and three of its degradation products, is shown in Figure 3.30. The presence of significant levels of background makes confirmation of the presence of any materials related to atrazine very difficult. The TIC traces from the constant-neutral-loss scan for 42 Da and the precursor-ion scan for m/z 68 are shown in Figure 3.31 and allow the signals from the target compounds to be located readily. 

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