A method was developed and validated for determination and quantitation of tilmicosin residues in swine, cattle, and sheep edible tissues, as well as chicken fat, skin, and muscle over a concentration range of 0.025 microg/g-20 microg/g. For chicken kidney and liver, the method was validated over a range of 0.060 microg/g-20 microg/g. The tissue sample was extracted with methanol and a C18 cartridge was used for solid-phase extraction cleanup. A reversed-phase gradient liquid chromatographic method with detection at 280 nm was used to separate the tilmicosin from matrix components in 30 min run time. The limit of quantitation (LOQ) of the method was 0.025 microg/g for all tested tissues except chicken kidney and liver, for which the LOQ was 0.06 microg/g. Average recoveries for tissue samples ranged from 73 to 98%. Relative standard deviation values ranged from 0.6 to 14.7%.

Adipose Tissue↗

PubMedDate not supplied

Focus film distance of remote control tables.

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Electricity↗

PubMedDate not supplied

A permanent internal fixation technique for the Austin osteotomy.

A new method of permanent internal fixation is described with a discussion of applicability to the Austin procedure for the surgical correction of hallux abducto valgus deformity. The contention of this article is that an easily performed wire fixation method provides superior stabilization of the Austin osteotomy site. Preliminary investigation of this method shows consistently fewer complications secondary to instability of the Austin osteotomy, with union of the osseous fragments proceeding more rapidly as compared to nonfixated osteotomies.

Fracture Fixation, Internal↗

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Determination of monensin in edible bovine tissues and milk by liquid chromatography.

A method is described for detection and quantitation of monensin in bovine tissues by liquid chromatography (LC) with postcolumn derivatization (PCD) with vanillin. Monensin is extracted from the tissues by homogenization with methanol-water and is isolated and concentrated by liquid-liquid partition and sorbent extraction with silica gel. Monensin is mixed postcolumn with vanillin under acidic conditions and heated, and the resulting products are measured by a variable-wavelength detector at 520 nm. The method has a limit of quantitation of 5 ppb monensin in milk and 25 ppb monensin in bovine muscle, liver, kidney, and fat. Standard recovery over the levels and matrixes tested ranged from 80 to 88%. The method is an improvement in specificity, accuracy, and analysis time over existing monensin residue methods for bovine tissues.

Animals↗

PubMedDate not supplied

Determination of tilmicosin in bovine and porcine sera by liquid chromatography.

A liquid chromatographic (LC) assay is described for determining tilmicosin in bovine and porcine blood sera. Tilmicosin is isolated from the serum matrix and purified by solid-phase extraction with C18 sorbent. Sample is analyzed by LC using a gradient system with a phenyl reversed-phase column that separates tilmicosin from the matrix in 30 min. Tilmicosin is measured by UV absorbance at 280 nm. Validation of assay included evaluation of accuracy, precision, linearity, specificity, sensitivity, range, and sample stability. The method has a limit of quantitation of 0.1 ppm and a validated range of 0.1 to 10.0 ppm. Recoveries were 91-95% for bovine serum and 85-93% porcine serum. The limit of detection was 0.05 microgram/mL. Limits of detection and quantitation were based on 3 and 6 times the baseline noise of control serum samples, respectively. Relative standard deviations of precision samples (n = 6) were 2% or less for both sera. The method has better specificity and analysis time than previous microbiological methods for tilmicosin in sera.

Animals↗