W e encourage our authors to consider the use of absolute quantitative 1 H NMR spectroscopy to determine the purity of biologically tested research compounds. The Perspective by Pauli et al. (DOI: 10.1021/jm500734a) in this issue provides an excellent overview of quantitative 1 H NMR spectroscopy methods and their use for purity determination. The major advantages of these techniques are that t...

Single molecule fluorescence experiments, with their associated low signals, require very low background fluorescence in the sample. Even high purity liquids will often possess large numbers of fluorescent impurities that are difficult to completely remove through standard purification techniques such as distillation and recrystallization. We have constructed a simple setup in which such impuri...

The control of impurities in Formulated products and Active Pharmaceutical ingredient’s were regulated by various regulatory authorities like US-FDA,ICH,MHRA,TGA etc.As per International Conference on Harmonization guidelines, the Impurity may be defined as any component of new drug product that is not the drug substance or an excipient in drug product. Nowadays apart from purity profile there ...

There has been an increasing trend in the production and consumption of local and imported fruit juices in Iran. The presence of impurities and foreign matter in finished products for human consumption is of great concern because they present health hazards when they exceed beneficial limits. The manufacture of juices requires special attention in terms of purity and the sources of water and it...

When starting a protein-crystallization project, scientists are faced with several unknowns. Amongst them are these questions: (i) is the purity of the starting material sufficient? and (ii) which type of crystallization experiment is the most promising to conduct? The difficulty in purifying active membrane-protein samples for crystallization trials and the high costs associated with producing...

Given the critical role of pure, organic compound primary reference standards used to characterize and certify chemical Certified Reference Materials (CRMs), it is essential that associated mass purity assessments be fit-for-purpose, represented by an appropriate uncertainty interval, and metrologically sound. The mass fraction purities (% g/g) of 25-hydroxyvitamin D (25(OH)D) reference standar...

Background 99mTc-mercaptoacetyl-triglycine (99mTc-MAG3) has been used for dynamic renal imaging since about 30 years. Free pertechnetate (99mTcO4), colloidal 99mTc ((99mTcO2)n), 99mTc-tartrate (precursor), precomplexes (99mTc-(MAG3)x) and lipophilic 99mTc-MAG2 are the main radiochemical impurities that may occur in the preparation. The total amount of these impurities has to be identified befor...

In view of an increasing number of generic drugs emerging, a comparative study was performed including the approved lisinopril preparations in the form of tablets marketed in Croatia, to compare purity profiles of generic drugs versus the original medicinal product. Several batches of each individual medicinal product at different stages of their shelf life were analyzed. Impurities were determ...

Absolute quantification of peptides is typically achieved using amino acid analysis, elemental analysis or derivatisation chemistry. Impurities, if present, may be accounted for using analytical high-performance liquid chromatography (HPLC) with detection of the peptide bond ultraviolet (UV) absorbance. To do this, peak areas from a UV chromatogram are used to estimate percentage purity on a ma...

PROBLEMS ASSOCIATED WITH processing whole sugarcane crop can be minimised by removing impurities during the clarification stage. As a first step, it is important to understand the colloidal chemistry of juice particles on a molecular level to assist development of strategies for effective clarification performance. This paper presents the composition and surface characteristics of colloidal par...