Ammonium acetate as a novel buffer for highly selective robust urinary HPLC-ICP-MS arsenic speciation methodology.

Ammonium acetate is employed in order to develop a novel HPLC-ICP-MS arsenic speciation methodology applicable to six arsenic species, i.e, AC, AB, AsIII, AsV, DMA and MMA. The most predominant species in the toxicological field are covered in a 30-min chromatogram with reproducible and repeatability peak area ratio. Moreover, typical problems from traditional methods are sorted out by using a robust, high-selective and 75ArCl+ interference-free methodology. Chromatographic and detector optimization ensures low LOQs for each species with acceptable precision and accuracy values obtained using four urinary arsenic speciation PTS enabling to be useful for sub ng mL-1 arsenic exposure assessments.

[Validation of an in-house method for the determination of zinc in serum: Meeting the requirements of ISO 17025]. / Propuesta de un procedimiento de validación de un método para la determinación de cinc sérico: cumplimiento de los requisitos de la ISO 17025.

OBJECTIVE: The aim of this report is to propose a scheme for validation of an analytical technique according to ISO 17025. MATERIAL AND METHODS: According to ISO 17025, the fundamental parameters tested were: selectivity, calibration model, precision, accuracy, uncertainty of measurement, and analytical interference. RESULTS: A protocol has been developed that has been applied successfully to quantify zinc in serum by atomic absorption spectrometry. CONCLUSION: It is demonstrated that our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.

Concentración de metales séricos (titanio, cromo y cobalto) en el seguimiento de las artroplastias totales de cadera / Serum metal (titanium, chromium and cobalt) concentrations in the follow-up of total hip arthroplasty

Objetivo: Analizar la degradación de los productos metálicos que constituyen las aleaciones de las prótesis de cadera. Pacientes y método: Se midió, mediante absorción atómica, el titanio, el cromo y el cobalto en la sangre de 58 pacientes con prótesis totales de cadera, compuestas por aleaciones de cromo y cobalto y de titanio, con o sin cementar. Se analizó la evolución de las concentraciones séricas preoperatorias, a los seis y a los 12 meses. Resultados: Encontramos una elevación significativa tras el inicio de la movilización de la articulación, pero sin afectación clínica. Los percentiles 95 de la distribución de concentraciones fueron para el Ti 27 mg/L, Cr 1 mg/L y Co 1,7 mg/L. Conclusión: La elevación de estas concentraciones podría ser indicativa de mal funcionamiento del implante o de desgaste excesivo que podría conducir a toxicidades locales o remotas (AU)

Objective: To analyze the degradation of the metal products contained in hip prosthesis alloys. Patients and method: Atomic absorption measurements were made of the titanium, chromium and cobalt concentrations in the blood of 58 patients with total hip replacement implants made of titanium, chromium and cobalt alloys with or without cementing. The evolution of the serum metal concentrations was assessed based on measurements obtained preoperatively and 6 and 12 months after surgery. Results: A significant increase in serum levels was noted after the start of joint mobilization, though without clinical repercussions. The percentile 95 values of the metal concentration distributions were 27 mg/l for titanium, 1 mg/l in the case of chromium, and 1.7 mg/l for cobalt. Conclusion: The rise in serum metal concentrations could be indicative of poor implant function or excessive wear that in turn could lead to local or disseminated toxicity (AU)

Qualitative and quantitative documentation of the racing performance of 461 Thoroughbred racehorses after arthroscopic removal of dorsoproximal first phalanx osteochondral fractures (1986-1995).

The purpose of this study was to examine the longevity of postoperative careers and quality of performance of 461 Thoroughbred racehorses after arthroscopic removal of dorsoproximal first phalanx (P1) osteochondral fractures. Six hundred and 59 dorsoproximal P1 chip fractures were removed arthroscopically from 574 joints in 461 horses presented for lameness or decreased performance attributed to the chip fractures. Radiological and arthroscopic examination revealed an average of 1.43 fragment sites/horse, 1.15 fragment sites/joint and 1.25 affected joints/horse. Eighty-nine percent of the horses (411/461) raced after surgery and 82% (377/461) did so at the same or higher class. Fifty horses did not race after surgery. Sixty-eight percent of the horses raced in a Stake or Allowance race postoperatively. Data, previously undocumented, establishes that the quantity and quality of performance is not diminished after arthroscopic treatment of dorsoproximal P1 fragmentation. Surgical removal of chip fractures is a means of preserving the economic value of an injured Thoroughbred, allowing a rapid and successful return to racing at the previous level of racing performance.