Analytical methods developments

The contemporary chromatograph used for analytical purposes is a very complex instrument that may operate at pressures up to 10,000 p.s.i.and provide flow rates that range from a few microliters per minute to 10 or 20 ml/minute. Solutes can be detected easily at concentration levels as low as lxlO-9 g/ml and a complete analysis can be carried out on a few micrograms of sample in a few minutes. The range of liquid chromatographs that is available extends from the relatively simple and inexpensive instrument, suitable for the majority of routine analyses, to the very elaborate and expensive machines that are more appropriate for analytical method development. 

This system includes measures and activities related to laboratory procedures, testing, analytical methods development and validation or verification, and the stability program. 

Low resolution MS yields specificity comparable to that of high resolution MS, if a relatively pure sample is delivered to the ion source. Either high resolution GC or additional sample purification is required. To obtain sufficient specificity, it is necessary to demonstrate that the intensities of the major peaks in the mass spectrum are in the correct proportions. Usually 10 to 50 ng of sample is required to establish identity unambiguously. Use of preparative GC for purification of nitrosamines detected by the TEA ( ) is readily adaptable to any nitrosamine present in a complex mixture and requires a minimum of analytical method development when new types of samples are examined. 

Third, in order to ensure that a collaborated method is being performed properly, and that resultant data obtained is sound, an appropriate set of controls or reference materials is needed to test the method as it is being used (Chase and Long 1997). However, there is a difference in how one views the aforementioned concepts. For example, analytical method development is a process-oriented approach in which each step of the process is continually tested whereas, the use of a RM, standard control or comparison with another method is a result-oriented view (Taimer et al. 1995). 

Currently, nutrient analytical methods development often utilizes the method of standard additions as an intrinsic aspect of the development process. Essentially, the analyte to be measured exists in the matrix to which an identical known pure standard is added. The spiked and non-spiked matrix is extracted and analysed for the nutrient of interest. By spiking at increasing levels the researcher can establish, to some degree of certainty, the recovery and linearity of the standard additions. One can also evaluate data to determine reproducibility, precision, and accuracy. Unfortunately, the method of standard additions does not allow the evaluation of the method at nutrient concentrations less than 100 % of the endogenous level. 

Chase and Long (1997) propose that this conundrum can be eliminated by the use of Zero Reference Materials (ZRMs) in analytical methods development to fully evaluate the method. A ZRM is a product matrix that lacks those nutrient components that are to be assayed, i.e. a blank matrix. The use of a ZRM in method development can and will give a true indication as to how the method will perform as the spiked nutrient levels approach zero. For example, two products. Corn Starch (NIST RM 8432) and Microcrystalline Cellulose (NIST RM 8416), contain very low elemental concentrations and could conceivably serve as real sample blanks or ZRMs in some analytical procedures. 

Regulatory guidance and scientific consideration for residue analytical method development and validation... 

The composition, properties and size (weight, volume) of the sample material to be analyzed are important aspects for analytical method development and for analyte enrichment vs depletion of sample matrix. 

J.A. Shoemaker, Analytical method development for alachlor ESA and other acetanilide herbicide degradation products, Presented at the 49th ASMS Conference, Chicago, IL, May 27-31, 2001. 

Accurate, precise and sensitive analytical methods are important to the collection of data needed for regulatory decisions about pesticide registration. This article describes the various components of analytical method development, validation and implementation that affect the collection of pesticide residue distribution data for regulatory assessment of environmental fate and water quality impacts. Included in this discussion are both the technical needs of analytical methods and the attributes of study design and sample collection needed to develop data that are useful for regulatory purposes. 

Decisions made in the design of field study data collection directly and indirectly affect analytical method development. Each sampling matrix will require specific procedures, and methods need to be developed with a view to the nature and scope of field monitoring programs that are or may be required. 

Fasano R, Randel M, Sadowski L, et al. 1982. Analytical methods development for dimethyl methylphosphonate, diisopropyl methylphosphonate, and trimethyl phosphate. Cambridge, MA Arthur D. Little, Inc. NTIS No. AD-A120-863. 

In the clinical area, the largest share of analytical methods development and publication has centered on the determination of theophylline in various body fluids, since theophylline is used as a bronchodilator in asthma. Monitoring serum theophylline levels is much more helpful than monitoring dosage levels.44 Interest in the assay of other methylxanthines and their metabolites has been on the increase, as evidenced by the citations in the literature with a focus on the analysis of various xanthines and methylxanthines. 

Contracting out of activities previously only conducted in-house is already becoming quite common and will probably continue to develop. In the past a so-called full-service pharmaceutical company took direct responsibility for all the activities required for the formulation, manufacture, quality control, and regulatory approval of its drug products. Nowadays the use of specialist contract houses to perform activities such as formulation, analytical methods development, manufacture of clinical trials supplies, supervision of the assembly of an NDA, postmarketing surveillance, and even troubleshooting may be contracted for even by some of the largest companies. 

Bulk API synthesis (GMP or non-GMP) including analytical methods development... 

Dr. Perry G. Wang is currently a principal scientist at Teleflex Medical. His interests include analytical method development and validation, medicated device products, and environmental engineering. His expertise focuses on high-throughput analysis of drugs and their metabolites in biological matrices with LC/MS/MS. 

Because FMs are semivolatile, they are amenable to analysis by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) without derivitization. Table 2 shows that all of the analytical methods developed to measure FMs in wastewater treatment to date utilize GC or GC-MS. 

Novel pyranoanthocyanins have also been isolated and identified in blackcurrant (Ribes nigrum) seed using HPLC, 2D NMR and ES-MS. Blackcurrant seeds were extracted with acetone-water (70 30, v/v) and the components of the extract were separated in a polyamide column followed by HPLC-DAD. The new pigments were finally separated in an MCI-HP20 column. The chemical structures of anthocyanins 1-2 and the novel pyranoanthocyanins 3-6 with the pyrano[4,3,2-de]-l-bcn/opyrylium core structure are shown in Fig. 2.110. It was stated that the analytical method developed separated well the novel pyranoanthocyanins [245],... 

There are four different drug products under Part II chemical active substance(s), radiopharmaceutical products, biological medicinal products, and vegetable medicinal products. For example, the GMP production report for biological medicinal products includes description of the genes used, strain of cell line, cell bank system, fermentation and harvesting, purification, characterization, analytical method development, process validation, impurities, and batch analysis (GMP production of biopharmaceuticals is described in Chapter 10). A DMF (Exhibit 8.8) is submitted. 

A rationale should be generated to explain and support the reasoning for validating the selected parameters. The use of reference standards during validation helps to reinforce the reliability of the analytical method developed. The conditions of how a test is performed may have a strong influence on the results. These conditions have to be recorded and followed. 

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