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Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648132 ◽

1991 ◽

Vol 65 (03) ◽

pp. 263-267 ◽

Cited By ~ 3

Author(s):

A M H P van den Besselaar ◽

R M Bertina

Keyword(s):

Reference Material ◽

Standard Error ◽

Standard Errors ◽

Sensitivity Index ◽

Long Term Stability ◽

Significant Bias ◽

The Mean ◽

The Relationship ◽

International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

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Effect of Concentration of Trisodium Citrate Anticoagulant on Calculation of the International Normalised Ratio and the International Sensitivity Index of Thromboplastin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648816 ◽

1994 ◽

Vol 72 (01) ◽

pp. 084-088 ◽

Cited By ~ 29

Author(s):

E M Duncan ◽

C R Casey ◽

B M Duncan ◽

J V Lloyd

Keyword(s):

Reference Material ◽

Oral Anticoagulants ◽

Reference Method ◽

Trisodium Citrate ◽

Sensitivity Index ◽

Blood Samples ◽

Orthogonal Regression ◽

Significant Difference ◽

International Normalised Ratio ◽

International Sensitivity Index

SummaryThe aim of this study was to determine whether the concentration of trisodium citrate used to anticoagulate blood has an effect on the INR of the sample and the ISI of the thromboplastin. Five thromboplastins including and Australian reference material were used to measure the prothrombin time of normal and patient samples collected into two concentrations of trisodium citrate - 109 mM and 129 mM. There was no effect of citrate concentration on the INRs determined with the reference material. However for the other four thromboplastins there was a significant difference between INRs for the two citrate groups. The prothrombin times of the samples collected into 129 mM were longer than those collected into 109 mM. This difference was only slight in normal plasma but more marked in patients receiving oral anticoagulants, causing the INRs for patient plasmas collected into 129 mM citrate to be higher then the corresponding samples collected into 109 mM citrate.From orthogonal regression of log prothrombin times by the reference method against each thromboplastin, we found that the ISI for each thromboplastin was approximately 10% lower when determined with samples collected into 129 mM citrate than with samples collected into 109 mM. These results suggest that the concentration of trisodium citrate used for collection of blood samples can affect the calculation of the INR and the calibration of the ISI of thromboplastin. This was found both for commercial thromboplastins prepared by tissue extraction and for a recombinant tissue factor.

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BIOASSAY CHARACTERISTICS OF INDIVIDUAL URINARY GONADOTROPHIN EXTRACTS

Acta Endocrinologica ◽

10.1530/acta.0.0420214 ◽

1963 ◽

Vol 42 (2) ◽

pp. 214-224

Author(s):

Raymond C. Mellinger ◽

Jalileh A. Mansour ◽

Richmond W. Smith

Keyword(s):

Reference Material ◽

Young Women ◽

Reference Standard ◽

General Acceptance ◽

Modifying Factors ◽

Large Numbers ◽

The World ◽

Quantitative Bioassay ◽

Different Parts ◽

Age And Sex

ABSTRACT A reference standard is widely sought for use in the quantitative bioassay of pituitary gonadotrophin recovered from urine. The biologic similarity of pooled urinary extracts obtained from large numbers of subjects, utilizing groups of different age and sex, preparing and assaying the materials by varying techniques in different parts of the world, has lead to a general acceptance of such preparations as international gonadotrophin reference standards. In the present study, however, the extract of pooled urine from a small number of young women is shown to produce a significantly different bioassay response from that of the reference materials. Gonadotrophins of individual subjects likewise varied from the multiple subject standards in many instances. The cause of these differences is thought to be due to the modifying influence of non-hormonal substances extracted from urine with the gonadotrophin and not necessarily to variations in the gonadotrophins themselves. Such modifying factors might have similar effects in a comparative assay of pooled extracts contributed by many subjects, but produce significant variations when material from individual subjects is compared. It is concluded that the expression of potency of a gonadotrophic extract in terms of pooled reference material to which it is not essentially similar may diminish rather than enhance the validity of the assay.

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ICP-MS AND ICP-AES ANALYSIS OF PLANT REFERENCE MATERIALS

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2019-85-6-11-24 ◽

2019 ◽

Vol 85 (6) ◽

pp. 11-24

Author(s):

I. V. Nikolaeva ◽

A. A. Kravchenko ◽

S. V. Palessky ◽

S. V. Nechepurenko ◽

D. V. Semenova

Keyword(s):

Reference Material ◽

Mass Spectrometer ◽

Reference Materials ◽

Atomic Emission ◽

Icp Ms ◽

Lithium Metaborate ◽

Relative Standard ◽

Microwave System ◽

Total Analysis ◽

Siberian Pine

Two methods — ICP-MS and ICP-AES are used for certification of the new reference material — needles of Siberian pine (NSP-1). Techniques of the analysis include decomposition of plant samples in two different ways: acid digestion in a microwave system MARS-5 and lithium metaborate fusion followed by ICP-MS and ICP-AES analysis of the solutions. Simultaneous determinations of all the elements were carried out in low, medium and high resolution using SF-mass-spectrometer ELEMENT and atomic-emission spectrometer IRIS Advantage with external calibrations and internal standards (In — ICP-MS, Sc —ICP-AES). Middle and high resolutions of ICP mass spectrometer were used for interference corrections. Data obtained by ICP-MS and ICP-AES with different decomposition techniques are in good agreement. The ICP-MS and ICP-AES techniques have been validated by the analysis of three plant reference materials: LB-1 (leaf of a birch), Tr-1 (grass mixture) and EK-1 (Canadian pondweed). These techniques were used for the determination of 38 elements in the new reference material NSP-1. Relative standard deviations for most of the determined elements were below 10%. Combination of ICP-MS and ICP-AES techniques for certification of the new reference material makes it possible to expand the set of elements to be determined and to reduce the total analysis time.

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