Laboratory practices

From the perspective of laboratory practice, the sensitivity of many indoles to acids, oxygen and light prescribes the use of an inert atmosphere for most reactions involving indoles and the avoidance of storage with exposure to light. This sensitivity is greatly attenuated by electron-withdrawing (EW) substituents. 

Quality control encompasses all activities used to bring a system into statistical control. The most important facet of quality control is written documentation, including statements of good laboratory practices, good measurement practices, standard operating procedures, and protocols for a specific purpose. 

Make a list of good laboratory practices for the lab accompanying this course (or another lab if this course does not have an associated laboratory). Explain the rationale for each item on your list. 

Most iron salts and compounds may be safely handled following common safe laboratory practices. Some compounds are irritants. A more serious threat is ingestion of massive quantities of iron salts which results in diarrhea, hemorrhage, fiver damage, heart damage, and shock. A lethal dose is 200 250 mg/kg of body weight. The majority of the victims of iron poisoning are children under five years of age. 

Standard reference materials provide a necessary but insufficient means for achieving accuracy and measurement compatibiUty on a national or international scale. Good test methods, good laboratory practices, well-qualified personnel, and proper intralaboratory and intedaboratory quaUty assurance procedures ate equally important. A systems approach to measurement compatibiUty is ikustrated in Figure 2. The function of each level is to transfer accuracy to the level below and to help provide traceabiUty to the level above. Thus traversing the hierarchy from bottom to top increases accuracy at the expense of measurement efficiency. 

The reviewer should estabHsh that the laboratory reporting the study has the necessary professional reputation, scientific experience, and expertise in the area investigated. It should be confirmed that adequate quaHty-control faciHties are in place and good laboratory practices and procedures foUowed. 

G. L. Kehl. The Principles ofMetallographic Laboratory Practice. McGraw-Hill, New York, 1949. 

All testing to support notification must be performed by methods specified in Annex V to Directive 79/831/EEC and in accordance with the principles of good laboratory practice (GLP). GLP is concerned with the organizational processes and conditions under which laboratory studies are planned, performed, monitored, recorded and reported. 

Laboratories wishing to claim GLP compliance are nonually registered with Competent Authorities who issue statements of compliance following successful periodic inspections of the premises to monitor compliance with the relevant legislation. In the UK compliance with the Good Laboratory Practice Regulations 1999 is audited by the Medicines Control Agency. 

SI 1999/3106 Health and Safety - The Good Laboratory Practice Regulations... 

Materials evaluation should be based only on actual data obtained at conditions as close as possible to intended operating environments. Prediction of a material s performance is most accurate when standard corrosion testing is done in the actual service environment. Often it is extremely difficult in laboratory testing to expose a material to all of the impurities that the apparatus actually will contact. In addition, not all operating characteristics are readily simulated in laboratory testing. Nevertheless, there are standard laboratory practices that enable engineering estimates of the corrosion resistance of materials to be evaluated. 

First, let us consider batch mixing processes, as exemplified by ordinaiy laboratory practice in solution kinetics. A portion of one solution (say, of the substrate) is added by pipet to a second solution (containing the reagent) in a flask, the flask is shaken to achieve homogeneity, and then samples are withdrawn at known times for analysis, or the solution is subjected to continuous observation as a function of time, for example, by spectrophotometry. For reactions on a time scale (measured by the half-life) of hours or even several minutes, the time consumed in these operations is a negligible portion of the reaction time, but as the half-life of the reaction decreases, it becomes necessary to consider these preliminary steps. Let us distinguish three stages ... 

Working areas within certain industrial buildings may have restricted access (i.e. sterile laboratories, radioactive areas). Separate toilet accommodation may be required in these areas, an assessment of which may be obtained from the operator and reference to such publications as Atomic Energy Code of Practice, Laboratory Practice. It may also be necessary to operate such appliances remotely by photoelectric cell, sonic control or foot control. 

Wolf, S., Guide to Electronic Measurements and Laboratory Practice, Prentice-Hall, Englewood Cliffs, NJ (1983). 

Technique Aspects of Carbohydrates, M. Stacey and P. J. Somers, Laboratory Practice, 18 (1969) 1172-1180. 

There are a number of other regulations/directives that you will need to consult, as appropriate. These address topics such as Good Laboratory Practice (GLP), Good Manufacturing Practice (GMP), the conduct of clinical trials, variations to authorised drugs, and the use of genetically modified organisms. A list of the most relevant directives is shown in Table 1.5. 

Directive 2004/10/EC of the European Parliament and of the Council of 11 February 2004 on the harmonisation of laws, regulations and administrative provisions relating to the application of the principles of good laboratory practice and the verification of their applications for tests on chemical substances... 

As vith human pharmaceuticals, all safety studies must be conducted in accordance vdth the principles of Good Laboratory Practice (GLP). Similar to the International Conference on Harmonisation (ICH), the Veterinary International Conference on Harmonisation (VICH) has developed agreed guidelines on the types of test and other considerations that need to be addressed during the development and evaluation of veterinary medicines. A list ofVICH guideline topics is provided in Table 7.1. 

Pharmaceutical products are designed and developed in a way that takes account of the requirements of Good Manufacturing Practice and Good Laboratory Practice. 

This section discusses the value of laboratory practical work in providing a sound basis for the development of an understanding of the triplet relationship. Whilst the first three chapters deal with the macro experience and show how progression to the submicro and symbolic can be faciUtated, the last starts from the opposite extreme and shows the value of working from the basis of diagrams. 

Significant problems have been identified in the science education literature about the laboratory/practical courses, in particular about the ineffectiveness of laboratory instruction in enhancing conceptual understanding (Hofstein, 2004 Hofstein Lunetta, 1982 2004). The type of laboratory instruction plays certainly an important role in this deficiency. 

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