ISO radiation sterilization standards

This presentation provides an overview of the current status of the ISO radiation sterilization standards. The ISO standards are voluntary standards which detail both the validation and routine control of the sterilization process. ISO 11137 was approved in 1994 and published in 1995. When reviewing the standard you will note that less than 20% of the standard is devoted to requirements and the remainder is guidance on how to comply with the requirements.

Future standards developments in radiation sterilization are being focused on providing additional guidance. The guidance that is currently provided in informative annexes of ISO 11137 includes: device/packaging materials, dose setting methods, and dosimeters and dose measurement, currently, there are four Technical Reports being developed to provide additional guidance:

1. 1. AAMI Draft TIR, “Radiation Sterilization Material Qualification”

2. 2. ISO TR 13409-1996, “Sterilization of health care products — Radiation sterilization — Substantiation of 25 kGy as a sterilization dose for small or infrequent production batches”

3. 3. ISO Draft TR, “Sterilization of health care products — Radiation sterilization Selection of a sterilization dose for a single production batch” li]4. ISO Draft TR, “Sterilization of health care products — Radiation sterilization-Product Families, Plans for Sampling and Frequency of Dose Audits.”

     

Comparison of phenyl-type columns in the development of a fast liquid chromatographic system for eighteen opiates commonly found in forensic toxicology

We report a precise and reliable method for the detection of 18 of the most commonly found opiates on the Belgian legal and illicit market, by ion-exchange, reversed-phase high-performance liquid chromatography, using a conventional phenyl-type analytical column (150x4.6 mm I.D., particle size 5 microm) and diode-array detection. We also describe a performance (efficiency and sensitivity) comparison of this column to a recently developed "high-speed" column (53x7.0 mm I.D., particle size 3 microm) packed with the same stationary phase, and used under slightly adjusted flow and gradient conditions. The final method, using the "high-speed" column, showed a significant reduction (55%) in analysis time without loss of resolution and sensitivity.     

Synthesis of the A-B subunit of angelmicin B

[reaction: see text] An efficient synthesis of the tricyclic A-B subunit 2 of angelmicin B is described. A formal three-component coupling of aldehydes 4 and 6 with gamma-silylallylborane 7 was employed to assemble the tetrahydrofuranyl core of 2, a strategy highlighted by the stereoselective [3 + 2] annulation of allylsilanes 5a/5b with aldehyde 4. The efficiency of the [3 + 2] annulation was greatly improved by using the allylic benzhydryldimethylsilane 5b compared to the allylic phenyldimethylsilane 5a.     

Determination of chloramphenicol in bovine milk by liquid chromatography/tandem mass spectrometry

A rapid confirmatory liquid chromatographic/tandem mass spectrometic method was developed for determination of chloramphenicol in bovine milk. Chloramphenicol was extracted directly from milk by solid-phase extraction on a C18 cartridge. The extract was further cleaned up on neutral aluminium oxide. Three transition products were monitored in negative ion mode after atmospheric pressure chemical ionization. The detection capability related to the transition product of lowest abundance was 0.03 microg/kg. The mean recovery was 90% at levels of 0.1-0.2 microg/kg. The relative repeatability standard deviations were 4.3, 3.8, and 2.8% at levels of 0.1, 0.2, and 1.0 microg/kg, respectively.     

Factors involved in the formation of amorphous and crystalline calcium carbonate: a study of an ascidian skeleton.

The majority of invertebrate skeletal tissues are composed of the most stable crystalline polymorphs of CaCO(3), calcite, and/or aragonite. Here we describe a composite skeletal tissue from an ascidian in which amorphous and crystalline calcium carbonate coexist in well-defined domains separated by an organic sheath. Each biogenic mineral phase has a characteristic Mg content (5.9 and 1.7 mol %, respectively) and concentration of intramineral proteins (0.05 and 0.01 wt %, respectively). Macromolecular extracts from various biogenic amorphous calcium carbonate (ACC) skeletons are typically glycoproteins, rich in glutamic acid and hydroxyamino acids. The proteins from the crystalline calcitic phases are aspartate-rich. Macromolecules extracted from biogenic ACC induced the formation of stabilized ACC and/or inhibited crystallization of calcite in vitro. The yield of the synthetic ACC was 15-20%. The presence of Mg facilitated the stabilization of ACC: the protein content in synthetic ACC was 0.12 wt % in the absence of Mg and 0.07 wt % in the presence of Mg (the Mg content in the precipitate was 8.5 mol %). In contrast, the macromolecules extracted from the calcitic layer induced the formation of calcite crystals with modified morphology similar to that expressed by the original biogenic calcite. We suggest that specialized macromolecules and magnesium ions may cooperate in the stabilization of intrinsically unstable amorphous calcium carbonate and in the formation of complex ACC/calcite tissues in vivo.     

Enhanced method performance due to a shorter chromatographic run-time in a liquid chromatography-tandem mass spectrometry assay for paclitaxel

Liquid chromatography-tandem mass spectrometry (LC-MS-MS) is often performed in a high-throughput environment. Unfortunately, with atmospheric pressure ionization (API) techniques, shorter run-times or reduced sample clean-up often result in ion or matrix suppression, which can lead to erroneous results. The present work on the analysis of paclitaxel compares ion suppression, sensitivity and linearity of a high-throughput LC-MS-MS method (0.8 min run-time, method B) to a method with increased separation (2.0 min run-time, method A). An atmospheric pressure chemical ionization (APCI) interface was used for both methods. The high-sample-throughput method uses an increased amount of organic solvent in the mobile phase (isocratic, 85% versus 70% of methanol) and a higher flow-rate (600 microl/min versus 400 micro/min). As a result, internal standard (docetaxel) and target analyte (paclitaxel) co-elute, close to, although separated from the solvent front. Ion suppression of both methods was evaluated by comparing pure standard to plasma and plasma containing a vehicle. Sensitivity and linearity were compared by injecting matrix matched calibration samples with both methods. Ion suppression by the vehicle Cremophor EL led to poor data quality for the standard method (A), while for the short method (B), ion suppression was compensated for by the co-eluting internal standard. The short method showed similar linearity but increased sensitivity by at least a factor five. This work provides a strategy to compensate for ion suppression without the use of labeled internal standards. In addition, a better sensitivity and a shorter run-time are noted.     

Multi-element neutron activation analysis measurements towards the geochemistry of particulate matter exchange between continent—Atmosphere—Ocean

Sampling of marine aerosol and ocean water particulate matter yields very small quantities of material. INAA is used for routine analysis since it provides measurements of as many as 25 elements and permits multiple use of the small samples. Results are given for the mean elemental composition of Atlantic marine aerosols and oceanic suspended matter. Such analyses are essential for the interpretation of global geochemical cycles.     

The Jost-Lehmann-Dyson representation for a wide class of local fields

The connection between solutions of the wave equation in +1 space-time dimensions and the support properties of the restriction to dimensions of their Fourier transforms is investigated for a class of functionals over function spaces which are supposed to contain some elements with compact support, and then, may describe a wide class of localizable quantized fields.     

Semiquantitative Autoradiographie mit Hilfe des Ringofens. II

Zusammenfassung Die bereits in einer früheren Mitteilung beschriebene Methode zur halb quantitativen Bestimmung radioaktiver Substanzen mit Hilfe der Chronoautoradiographie wird weiter ausgeführt. Die Genauigkeit und die Empfindlichkeit der Methodik wurden diskutiert und eine Reihe verschiedener Anwendungsbeispiele beschrieben, insbesondere die Anwendung einer aus einem Nuklid hergestellten Standardskala zur Bestimmung anderer Nuklide. Die experimentelle Ermittlung des dazu benötigten Nuklidumrechnungsfaktors wird beschrieben.

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Summary The method described in a previous communication for the semi-quantitative determination of radioactive materials with the aid of chronoautoradiography is further developed. The precision and the sensitivity of the methodology are discussed and a number of instances of application are described, especially the use of a standard scale prepared from an isotope for the determination of other isotopes. The experimental determination of the required isotope conversion factor is described.

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Résumé On a de nouveau étudié la méthode décrite dans une communication précédente pour le dosage semiquantitatif de substances radioactives au moyen de la chronoautoradiographie. On a discuté l'exactitude et la sensibilité de la méthode et décrit une série de plusieurs exemples d'applications, en particulier l'utilisation d'une échelle étalon préparée à partir d'un isotope pour le dosage d'autres isotopes. On décrit la recherche expérimentale du facteur de conversion isotopique nécessaire pour cela.