Development of Fucosterol Certified Reference Material / 中国实验方剂学杂志

Objective:According to the GB/T 15000.3-2008， to develop a fucosterol certified reference material based on the project approved by Standardization Administration. Method:Fucosterol was isolated from <italic>Laminaria japonica</italic> dried thallus via 95% ethanol extraction， vacuum concentration， repeated column chromatography separation， recrystallization in petroleum ether-ethyl acetate， and residual solvent removal. Its chemical structure was identified by elemental analysis （EA）， infrared spectrum （IR）， mass spectrometry （MS）， nuclear magnetic resonance （NMR） and X-ray diffraction （XRD）. Its homogeneity， stability， and cooperative certification conducted by 8 laboratories were carried out by high performance liquid chromatography with evaporative light scattering detector. Result:For the fucosterol reference material， the certified value of purity was 99.54% with expanded uncertainty of 0.16% in confidence interval of 95%， the stability was good within 24 months storage period at 2-4 ℃， which met the technical requirements of reference material and passed the acceptance organized by Standardization Administration. Conclusion:The national standard materials of fucosterol has been successfully developed， which can be used for the determination of this component， the evaluation of detection methods， and the detection and quality control of related products.

Preparation and purification of Cry1Ah protein candidate reference material / 生物工程学报

With the rapid development of transgenic technology, the safety of genetically modified products has received extensive attention. Certified reference materials for the detection of genetically modified organisms play important roles in ensuring comparability and traceability of the qualitative and quantitative detection of genetically modified products. However, the development of protein reference materials is relatively slow, and one of the difficulties is the preparation of protein candidates with high purity. The cry1Ah1 gene of Bacillus thuringiensis has been used for the development of transgenic insect-resistant crops because of its excellent insecticidal activity against lepidopteran pests such as Asian corn borer, and has obtained transgenic lines with good insect resistance traits. In order to develop Cry1Ah protein certified reference material, it is urgent to establish a preparation and purification system. In this study, a system for preparing Cry1Ah protein by Bt expression system was optimized, and a high-purity Cry1Ah protein (size exclusion chromatography purity: 99.6%) was obtained by ion-exchange chromatography and size exclusion chromatography stepwise purification. The results of biological activity assay showed that there was no significant difference in the insecticidal activity of purified Cry1Ah protein and protoxin against diamondback moths (Plutella xylostella). Finally, the amino acid sequence of the activated Cry1Ah protein was determined using Edman degradation and mass spectrometry. In summary, the obtained Cry1Ah pure protein can be used for the development of protein reference materials.

Evaluation of a fungal collection as certified reference material producer and as a biological resource center

Abstract Considering the absence of standards for culture collections and more specifically for biological resource centers in the world, in addition to the absence of certified biological material in Brazil, this study aimed to evaluate a Fungal Collection from Fiocruz, as a producer of certified reference material and as Biological Resource Center (BRC). For this evaluation, a checklist based on the requirements of ABNT ISO GUIA34:2012 correlated with the ABNT NBR ISO/IEC17025:2005, was designed and applied. Complementing the implementation of the checklist, an internal audit was performed. An evaluation of this Collection as a BRC was also conducted following the requirements of the NIT-DICLA-061, the Brazilian internal standard from Inmetro, based on ABNT NBR ISO/IEC 17025:2005, ABNT ISO GUIA 34:2012 and OECD Best Practice Guidelines for BRCs. This was the first time that the NIT DICLA-061 was applied in a culture collection during an internal audit. The assessments enabled the proposal for the adequacy of this Collection to assure the implementation of the management system for their future accreditation by Inmetro as a certified reference material producer as well as its future accreditation as a Biological Resource Center according to the NIT-DICLA-061.

Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis

This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid.

Purity Determination and Uncertainty Evaluation of Ribavirin Purity Reference Material / 医药导报

Objective To develop the ribavirin purity certified reference material( CRM ) which has measurement traceability and high accuracy,and establish an effective method of evaluation. Methods The homogeneity and the stability were checked by differential scanning calorimetry(DSC). High performance liquid chromatography(HPLC)and DSC methods were used for purity determination of ribavirin. Results Ribavirin showed satisfactory homogeneity and stability. The certified value of ribavirin was 99. 5%with an uncertainty of 0. 4%(k=2,P=0. 95). Conclusion Ribavirin purity CRM obtained in this paper has been proven to be a national primary CRM with high accuracy and traceability,which can be used to validate analytical methods,improve the accuracy of measurement data,establish meteorological traceability of analytical results as well as control the quality of ribavirin in the pharmaceutical industry.

Estimación de la incertidumbre para el análisis de potencia de insulina humana isofana ADN recombinante por cromatografía liquida de alta resolución fase reversa según USP34 NF29 2011 / Uncertainty estimation for the USP34 NF29 2011 analysis of potency recombinant DNA isophane human insulin from PR-HPLC

El propósito de una medición es determinar el valor de una magnitud, llamada el mensurando. La imperfección natural de las mediciones, hace imposible conocer con certeza absoluta el valor verdadero de una magnitud, ya que toda medición lleva implícita una incertidumbre, el cual es un parámetro no negativo que caracteriza la dispersión de los valores atribuidos a un mensurando. En la presente investigación se empleo una estrategia diferente al procedimiento “bottom-up” propuesto por la ISO, el cual nos permitió estimar de forma global la incertidumbre, mediante la agrupación de valores determinados durante la verificación del método analítico. El valor obtenido en nuestro estudio fue de 3.46 UI/mL con un 90% de confianza. Observándose como fuente de mayor contribución al cálculo, el efecto de la matriz del medicamento, dependiente del tipo de insulina presente, además de la precisión y trazabilidad del patrón de referencia, los cuales contribuyen en la incertidumbre final de forma similar. En este sentido, nuestros esfuerzos deben dirigirse a la optimización de los procesos de homogeneización, adquisición del patrón de referencia tipo primario, con la finalidad de garantizar a lo largo del tiempo, resultados reproducibles, trazables y confiables.

The purpose of measurement is to determine the value of a quantity, called the measurand. The natural imperfection of determining measurements, makes impossible to know with absolute certainty the true value of a magnitude, since all measurement implies an uncertainty, which is a non-negative parameter that characterize the dispersion of the values attributed to a measurand. In this research, we employed a different strategy to the "bottom-up" procedure, proposed by the ISO, which allowed us to calculate globally the uncertainty, by grouping values, determined during the verification of the analytical method. The obtained value in our study was 3.46 IU/mL with 90% confidence. The matrix effect of the drug, depending on the insulin type present inside, was observed as the bigger contribution source to the calculation, as well as the accuracy and traceability of the reference pattern, which contribute in the final uncertainty similarly. Thus, our efforts should be directed to the optimization of the homogenization processes and the acquisition of the primary type reference pattern, in order to ensure over time, reproducible, traceable and reliable results.