Cross contamination effects

Contaminants Concentration in the zones, cross-contamination effects... 

Processing of herbal materials may generate dust or material which is susceptible to pest-infestation or microbiological contamination and cross-contamination. Effective cleaning of the equipment is therefore particularly important. 

Varying the target and substrate geometry they succeeded in obtaining various metal contents in the films. They reported cross-contamination effects in the case of PTFE/ metal targets. 

A three-position flask (Demo flask) may be used to simulate three exposure locations simultaneously fully immersed, vapor, and condensate. For the condensate part of the exposure, coupons can be exposed to drips of condensate directly under a condenser, or they cem be immersed in a heel of condensate before it is returned to the working container or sent elsewhere. When cross contamination effects are likely, the coupons should be exposed to the drips, not to the heel, and the coupons should be exposed in sequence that minimizes cross contamination effects. See Fig. 9 for sketch of a three-position flask. 

Cross-contamination between successive samples (vessel wall effects)... 

There must be an effective separation of rooms to prevent cross-contamination, about which measures shall be taken. Particular care shall be taken when sampling and tests and/or calibrations are undertaken at sites other than a permanent laboratory facility. The technical requirements for accommodation and environmental conditions that can affect the results of tests and calibrations shall be documented. The access to the laboratory shall be restricted to authorised persormel only. If customers or other people visit the laboratories they must be accompanied. The extent of control is based on the parlictrlar circrrmstances. 

To describe the procedure to ensure effective cleaning of parenteral manufacturing equipment to minimize the chances of cross-contamination and unacceptable viable count... 

Carryover. Small amounts of analyte may get carried over from the previous injection and contaminate the next sample to be injected [10]. The carryover will affect the accurate quantitation of the subsequent sample. The problem is more serious when a dilute sample is injected after a concentrated sample. To avoid cross-contamination from the preceding sample injection, all the parts in the injector that come into contact with the sample (the injection loop, the injection needle, and the needle seat) have to be cleaned effectively after the injection. The carryover can be evaluated by injecting a blank after a sample that contains a high concentration of analyte. The response of the analyte found in the blank sample expressed as a percentage of the response of the concentrated sample can be used to determine the level of carryover. Caffeine can be used for the system carryover test for assessing the performance of an injector and serves as a common standard for comparing the performance of different injectors. 

Cleaning systems must be designed in such a way that cross-contamination of the effective medicinal contents of the products is precluded. For this reason, CIP systems of types 2 and 3 are recommended. 

The use of non-disposable sampling equipment creates a potential for crosscontamination between samples. To eliminate the risk of cross-contamination, we must always decontaminate non-disposable sampling equipment and collect and analyze equipment blank samples to document the effectiveness of decontamination. Sampling containers that are not precleaned by the manufacturer must be also decontaminated prior to sampling. 

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