Analysis of thyreostatic drugs in thyroid samples by liquid chromatography tandem mass spectrometry: comparison of two sample treatment strategies.

A method based on ultra-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry (UPLC-MS/MS) for the determination of six thyreostatic drugs in thyroid tissue has been optimised and validated in accordance with Decision 2002/657/EC. Sample extraction was evaluated in methanol and in ethyl acetate, the latter which gave better results. Two clean-up strategies were compared: one based on silica cartridges (SPE), and the other, on gel permeation chromatography (GPC). Recoveries ranged from 40% to 79% for the SPE approach and from 80% to 109% for GPC. Quantification was performed with blank tissue samples spiked with the analytes in the range 50-500microgkg(-1). 5,6-Dimethyl-2-thiouracil and 2-mercaptobenzimidazole-d(4) were used as internal standards. Decision limit (CCalpha) and detection capability (CCbeta) ranged from 1 to 15microgkg(-1) and from 6 to 25microgkg(-1), respectively. The accuracy of the method was calculated as percent error, which was less than 10%. The relative standard deviation in reproducibility conditions ranged between 2% and 14%.

Analysis of thyreostatic drugs in thyroid samples by ultra-performance liquid chromatography tandem mass spectrometry detection.

A method based on ultra-performance liquid chromatography-electrospray ionisation-tandem mass spectrometry for the determination of six thyreostatic drugs in thyroid tissue has been optimised and validated in accordance with the Decision 2002/657/EC. Samples are extracted with methanol and the extracts cleaned-up on silica cartridges. The recoveries range from 40% for 6-phenyl-2-thiouracil to 79% for 2-thiouracil. Quantification is carried out with blank tissue samples spiked with the analytes in the range 25-500 microg kg(-1). 5,6-Dimethyl-2-thiouracil is used as internal standard. CCalpha and CCbeta are in the ranges 4.3-16.1 microg kg(-1) and 8.7-20.7 microg kg(-1), respectively. Accuracy, expressed as percentage of error, is lower than 6% and relative standard deviation in reproducibility conditions falls between 5.6 and 10.3%. Nowadays, the proposed method is routinely implemented in the laboratory of the Agència de Salut Pública de Barcelona and allows processing of up to 20 samples per day.

A critical review of the quality and safety of BADGE-based epoxy coatings for cans: implications for legislation on epoxy coatings for food contact.

BADGE-based epoxy resins have been commercially available for more than 40 years. They are extremely versatile, finding applications in many fields in both thermal and ambient cure applications. The present review focuses on their use in the food industry as surface coatings for food and beverage cans, and in particular on their chemical stability in relation to their toxicology and sensorial effects on foods. The implications of these properties of epoxy resins for prospective EU legislation on plastic coatings for food contact is discussed.

Cis/Trans Reactivity: Epoxy-Amine Systems.

The reactivities of cis and trans isomers of 1,2-diaminocyclohexane (1,2-DCH)/epoxy resin were studied separately. We found that the primary amine hydrogen disappears in both isomers at a similar rate when they react with an epoxy resin. However, the formation of tertiary amines differs considerably. The reactivity of the second amine hydrogen for the trans isomer is greater than that for the cis isomer, and this difference is observed as the reaction proceeds. The main reason for the slower disappearance of the cis secondary amine is steric hindrance and this fact is observed in the preexponential factors, glass transition temperatures (Tg), and ratio of rate constants of secondary to primary amine (R). The reaction was followed by Fourier transform infrared spectroscopy in the near-infrared range. The values of Tg were obtained by differential scanning calorimetry.

Overall migration and specific migration of bisphenol A diglycidyl ether monomer and m-xylylenediamine hardener from an optimized epoxy-amine formulation into water-based food simulants.

The overall and specific migrations of BADGE n = 0 monomer and m-XDA hardener from a BEPOX LAB 889 (Gairesa internal code), epoxy system cured at room temperature, into three water-based food simulants are studied. Hydrolysis of BADGE n = 0 was observed in all of these simulants, giving more polar products. We thus propose changing the EEC Directives, which at present only legislate for levels of BADGE n = 0 monomer in the simulants, to include the hydrolysis products of BADGE monomers. Another alternative would be to express all the migration levels due to BADGE and its derived products in terms of BADGE itself.

[Statistical study of a series of cryptorchism cases]. / Estudio estadístico de una serie de criptorquidias.

A study was made on a series of 348 patients with uni- and bilateral cryptorchid, a right location being predominant in the former cases, and in the canaliculus the most common testicular one. The associated pathology is usually irrelevant. In view of the results revealed by optical and ultrastructural histological study, the introduction of definitive corrective medical treatment appears to be essential within 2 years. Despite existing discrepancies with regard to dosage and efficacy of hormonal therapy with HCG or LH-RH analogues we believe they should be used at doses no higher than 12000 IU of HCG in order to achieve a decrease or ease the surgical treatment. Higher doses would damage the testicle or produce early puberty with growth failure. Scrotum-bound funiculolysis is the procedure accomplishing a larger amount of therapeutic success and in our experience the results are conditioned to the testicle's anatomic location. In the event of abdominal testicles or with high canaliculus location, a section of the spermatic canals could be performed followed later by auto-transplantations using microsurgery procedures.