A Systems Approach to Management

A procedure is outlined for deciding the mix of price and variable non-price features, such as quality, delivery, service or financing, to be included in a bid. The level of each non-price feature is set independently by comparing incremental spending against the alternative price reduction and basing the choice on value to the faction in the customer organization expected to dominate in the choice of the successful bid. Divergence from competition on all non-price features, both fixed and variable, is then taken into account in setting price by calculating a net price equivalent of feature differences as against each competitor. For any given markup the probability of success against a competitor over whom there is a net advantage is the same as that for an equivalently lower markup were price to be the sole basis for allocating the order.     

Measurement of particle size distribution in the discrete phase of high-impact polystyrene. II. An improved coulter counter procedure

An improved Coulter Counter procedure is described for determining the size distribution and volume fraction of the elastomeric discrete phase in high-impact polystyrene. The method isolates the discrete phase from a dispersion of the whole polymer in DMF by centrifugation and redisperses the discrete phase in an aqueous surfactant solution, thus allowing the particles to deswell and resume the dimensions they had in the polystyrene matrix. By measuring a Coulter Counter size distribution on the aqueous dispersion, a discrete-phase volume fraction can be reliably derived for the original impact polystyrene. The method is rapid and precise.     

Characterization of amino acids using Raman spectroscopy

A key process in the development of new drugs is elucidation of the interaction between the drug molecule and the target protein. Such knowledge then makes it possible to make systematic structural modifications of the drug molecule to optimize the interaction. Many analytical techniques can be applied to proteins in solution such as circular dichroism, ultraviolet, and fluorescence spectroscopy but these all have limitations. In this paper, we investigate the feasibility of using relatively simple, visible light Raman spectroscopic methods to investigate amino acids and related biopolymers.     

Elucidation of a low spin cobalt(II) system in a distorted tetrahedral geometry

We have prepared a series of divalent cobalt(II) complexes supported by the [PhBP(3)] ligand ([PhBP(3)] = [PhB(CH(2)PPh(2))(3)](-)) to probe certain structural and electronic phenomena that arise from this strong field, anionic tris(phosphine) donor ligand. The solid-state structure of the complex [PhBP(3)]CoI (1), accompanied by SQUID, EPR, and optical data, indicates that it is a pseudotetrahedral cobalt(II) species with a doublet ground state-the first of its type. To our knowledge, all previous examples of 4-coordinate cobalt(II) complexes with doublet ground states have adopted square planar structure types. Complex 1 provided a useful precursor to the corresponding bromide and chloride complexes, ([PhBP(3)]Co(mu-Br))(2), (2), and ([PhBP(3)]Co(mu-Cl))(2), (3). These complexes were similarly characterized and shown to be dimeric in the solid-state. In solution, however, the monomeric low spin form of 2 and 3 dominates at 25 degrees C. There is spectroscopic evidence for a temperature-dependent monomer/dimer equilibrium in solution for complex 3. Furthermore, the dimers 2 and 3 did not display appreciable antiferromagnetic coupling that is typical of halide and oxo-bridged copper(II) and cobalt(II) dimers. Rather, the EPR and SQUID data for solid samples of 2 and 3 suggest that they have triplet ground states. Complexes 1, 2, and 3 are extremely oxygen sensitive. Thus, stoichiometric oxidation of 1 by dioxygen produced the 4-coordinate, high spin complex [PhB(CH(2)P(O)Ph(2))(2)(CH(2)PPh(2))]CoI, (4), in which the [PhBP(3)] ligand had undergone a 4-electron oxidation. Reaction of 1 with TlOAr (Ar = 2,6-Me(2)Ph) afforded an example of a 4-coordinate, high spin complex, [PhBP(3)]Co(O-2,6-Me(2)Ph) (5), with an intact [PhBP(3)] ligand. The latter two complexes were spectroscopically and structurally characterized for comparison to complexes 1, 2, and 3. Our data for these complexes collectively suggest that the [PhBP(3)] ligand provides an unusually strong ligand-field to these divalent cobalt complexes that is chemically distinct from typical tris(phosphine) donor ligand sets, and distinct from tridentate borato ligands that have been previously studied. Coupling this strong ligand-field with a pronounced axial distortion away from tetrahedral symmetry, a geometric consequence that is enforced by the [PhBP(3)] ligand, provides access to monomeric [PhBP(3)]CoX complexes with doublet rather than quartet ground states.     

Derivatization of secondary amines with 2-naphthalene-sulfonyl chloride for high-performance liquid chromatographic analysis of spectinomycin

A normal-phase high-performance liquid chromatographic (HPLC) method has been developed for the assay of spectinomycin hydrochloride and spectinomycin sulfate for detection at 254 nm. The method involves pre-column derivatization of secondary amines of spectinomycin with 2-naphthalenesulfonyl chloride (NSCl) using a catalyst. Lincomycin, 1-methylpyrrole, 2-acetyl-1-methylpyrrole, and 2-acetyl-pyrrole act as catalysts for sulfonylation of spectinomycin. Without a catalyst, the derivatization reaction forms a considerable amount of actinospectinoic acid, a degradation compound of spectinomycin, and peak area:weight ratio of the derivative is approximately 15% lower than those with the catalyst. Following derivatization the sample is extracted and chromatographed on a normal-phase silica column with detection at 254 nm. The method is applicable for the analysis of both the hydrochloride and sulfate salt forms of spectinomycin. All the known degradation compounds of spectinomycin such as actinamine, actinospectinoic acid and the biosynthesis intermediates, dihydrospectinomycin diastereoisomers, are completely separated with this method. Mass spectrometric data confirms that spectinomycin is derivatized with NSCl at the secondary amines located at positions 6 and 8 of the ring structure. The standard curves for the HPLC assay of spectinomycin hydrochloride and sulfate are linear with correlation coefficients of 0.9997 and 0.9999, respectively over the range of 0.05 mg/ml to 0.3 mg/ml. The relative standard deviations (R.S.D.) of the HPLC assay methods for spectinomycin hydrochloride and sulfate are 0.67% and 0.86%, respectively. Spectinomycin hydrochloride and sulfate bulk drugs were assayed by the HPLC method and compared to gas-liquid chromatography and microbiological assay results. The HPLC method was used to assay spectinomycin in a veterinary formulation, Linco-Spectin soluble powder. The sensitivity of the HPLC assay was determined to be approximately 4 ng sample load on the column, which suggests applicability in serum and residue level studies.     

1:1 Complexes of octafluoronaphthalene with trans-stilbene and trans-azobenzene

Co-crystallisation of octafluoronaphthalene (OFN) with trans-stilbene or trans-azobenzene from solutions yielded 1:1 molecular complexes, shown by single-crystal X-ray diffraction to contain infinite stacks of near-parallel and planar, alternating OFN and trans-stilbene or trans-azobenzene molecules.