Analytical Quality Assessment Research Articles

Development and Greenness Assessment of Analytical Quality by Design Optimised Eco-friendly UV Spectrophotometric Methods for Analysis of Two Natural Antioxidants in Pure and Formulation

Utilizing analytical quality by design and green analytical chemistry principles, the present work introduces simple, robust, and environmentally benign UV methods. Two separate spectrophotometric methods were developed for the estimation of Silybin and Curcumin, where solvent, scan speed, and sampling interval are the estimated critical parameters. The detection was carried out at absorption maxima of 288nm for Silybin and 419nm for Curcumin with ethanol. To determine the critical method variables, a risk assessment was carried out using an Ishikawa diagram. Developed spectrophotometric methods were validated according to the International Council for Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use Q2 (R1) guidelines. The proposed methods showed good predictability and robustness. The new methodologies were found to be green according to the analytical greenness metric approach and software, the green analytical procedure index, and analytical eco-scale tools in comparison to the existing methods.

Assessment of Analytical Quality through Sigma Metrics & its Application for Selection of Westgard Rule

Assessment of Analytical Quality through Sigma Metrics & its Application for Selection of Westgard Rule

Chemometric Analysis of UV-Visible Spectral Fingerprints for the Discrimination and Quantification of Clinical Anthracycline Drug Preparation Used in Oncology.

In clinical treatment, the analytical quality assessment of the delivery of chemotherapeutic preparations is required to guarantee the patient's safety regarding the dose and most importantly the appropriate anticancer drug. On its own, the development of rapid analytical methods allowing both qualitative and quantitative control of the formulation of prepared solutions could significantly enhance the hospital's workflow, reducing costs, and potentially providing optimal patient care. UV-visible spectroscopy is a nondestructive, fast, and economical technique for molecular characterization of samples. A discrimination and quantification study of three chemotherapeutic drugs doxorubicin, daunorubicin, and epirubicin was conducted, using clinically relevant concentration ranges prepared in 0.9% NaCl solutions. The application of the partial least square discriminant analysis PLS-DA method on the UV-visible spectral data shows a perfect discrimination of the three drugs with a sensitivity and specificity of 100%. The use of partial least square regression PLS shows high quantification performance of these molecules in solution represented by the low value of root mean square error of calibration (RMSEC) and root mean square error of cross validation (RMSCECV) on the one hand and the high value of R-square on the other hand. This study demonstrated the viability of UV-visible fingerprinting (routine approach) coupled with chemometric tools for the classification and quantification of chemotherapeutic drugs during clinical preparation.

Does each bead count? A reduced-cost approach for recovering waterborne protozoa from challenge water using immunomagnetic separation.

Giardia duodenalis and Cryptosporidium spp. are two of the most prominent aetiological agents of waterborne diseases. Therefore, efficient and affordable methodologies for identifying and quantifying these parasites in water are increasingly necessary. USEPA Method 1623.1 is a widely used and validated protocol for detecting these parasites in water samples. It consists of a concentration step, followed by parasite purification and visualization by immunofluorescence microscopy. Although efficient, this method has a high cost particularly due to the immunomagnetic separation (IMS) step, which is most needed with complex and highly contaminated samples. Based on this, the present study aimed to determine whether it is possible to maintain the efficiency of Method 1623.1 while reducing the amount of beads per reaction, using as a matrix the challenge water recommended by the World Health Organization. As for Giardia cysts, a satisfactory recovery efficiency (RE) was obtained using 50% less IMS beads. This was evaluated both with a commercial cyst suspension (56.1% recovery) and an analytical quality assessment (47.5% recovery). Although RE rates obtained for Cryptosporidium parvum did not meet Method 1623.1 criteria in any of the experimental conditions tested, results presented in this paper indicated the relevance of the described adaptations, even in challenge water.

Plasma creatinine medians from patients partitioned by gender and age used as a tool for assessment of analytical stability at different concentrations

Background Monthly medians of patient results are useful in assessment of analytical quality in medical laboratories. Separate medians by gender makes it possible to generate two independent estimates of contemporaneous errors. However, for plasma creatinine, reference intervals (RIs) are different by gender and also higher over 70 years of age. Methods Daily, weekly and monthly patient medians were calculated from the raw data of plasma creatinine concentrations for males between 18 and 70 years, males >70 years, females between 18 and 70 years and females >70 years. Results The medians of the four groups were all closely associated, with similar patterns. The mean of percentage bias from each group defined the best estimate of bias. The maximum half-range (%) of the bias evaluations provided an estimate of the uncertainty comparable to the analytical performance specifications: thus, bias estimates could be classified as optimum, desirable or minimum quality. Conclusions Medians by gender and age are useful in assessment of analytical stability for plasma creatinine concentration ranging from 60 to 90 μmol/L. The daily medians are valuable in rapid detection of large systematic errors, the weekly medians in detecting minor systematic errors and monthly medians in assessment of long-term analytical stability.

Analytical quality assessment and method comparison of two immunoassays for the measurement of serum cardiac Troponin I in dogs and cats.

Cardiac troponin I (cTnI) is a sensitive and specific biomarker for myocardial injury. Validation of point-of-care (POC) analyzers for cTnI measurement is valuable to the critical care setting, in which rapid results can facilitate prompt diagnoses. An immunoassay for detecting cTnI is available for the POC AIA-360 analyzer (Tosoh Bioscience), but this has not been validated using canine and feline serum. The objectives were (a) to determine precision, accuracy, and linearity of cTnI measurement using the AIA-360 immunoassay in pooled canine and feline samples, and (b) to compare results for individual canine and feline samples with those obtained using a reference chemiluminescence method (Immulite 1000, Siemens). Intra- and inter-assay repeatability was determined using pooled canine and feline samples, and the coefficient of variation (CV) was calculated for each. Pooled samples were also serially diluted to assess linearity. A modified spike and recovery analysis was performed by mixing pooled samples with different concentrations. Bland-Altman and Deming regression analyses were used to determine bias for individual samples, and the total observed error (TEobs ) was calculated. Coefficient of variation values were well within the required maximum of 20%. Linearity was demonstrated over the range of samples tested, and the recovery study showed minimal proportional inaccuracies. Although the correlation between the analyzers was excellent, there was a large mean bias due to relative proportional bias. Total observed error consequently exceeded the total allowable error (TEA ). Although, in most respects, the analyzer demonstrated adequate performance, pronounced bias contributed to the large TEobs , indicating a requirement for analyzer-specific reference intervals.

Analytical Quality Assessment, Microbial Activity and Shelf Life Determination of Commercial Butter Samples in India

This study aimed to train the master level students for carrying out the research work as a part of minor research project based learning. In this the quality assessment of butter samples obtained from the local super market in India was performed. Thirty different butter samples (commercially available) were analyzed. Quality assessment was carried out by calculation of the Reichert-Meissl (RM) value. Microbiological activity was also tested by storing the samples in two different temperatures: room temperature and refrigerated conditions. Based on the RM value and microbial activity data taken for a period of six consecutive months, self life of the butter samples were calculated to estimate the appropriate storage period and conditions suitable for consumption.

Analytical quality assessment and method comparison of immunoassays for the measurement of serum cobalamin and folate in dogs and cats.

Serum cobalamin and folate are often measured in cats and dogs as part of laboratory testing for intestinal disease, small intestinal dysbiosis, or exocrine pancreatic deficiency. We performed an analytical validation of human immunoassays for cobalamin and folate measurement (AIA-900 analyzer, Tosoh Bioscience) and compared results with those obtained using chemiluminescence assays (Immulite 2000 analyzer, Siemens Medical Solutions Diagnostics). Accuracy, precision, total observable error (TEobs%), and σ values were calculated for the immunoassays. Correlation and agreement were evaluated with Deming regression, Passing-Bablok regression, and Bland-Altman analysis. Cobalamin intra-assay and inter-assay CVs were 1.8-9.3% and 2.6-6.8%, respectively. Folate intra-assay and inter-assay CVs were 1.5-9.1% and 3.4-8.1%, respectively. TEobs (%) were ≤19 and ≤31 for cobalamin and folate, respectively. Sigma values were 3.60-11.50 for cobalamin and 2.90-7.50 for folate. Regression analysis demonstrated very high or high correlations for cobalamin [ r = 0.98 (dogs), 0.97 (cats)] and folate [ r = 0.88 (dogs), 0.92 (cats)] but Bland-Altman analysis revealed poor agreement for both. The immunoassays had good analytical performance for measuring cobalamin and folate in both species. Results obtained by the 2 analyzers cannot be used interchangeably and should be interpreted using instrument-specific reference intervals. Further studies are required to establish immunoassay-specific reference intervals and to evaluate the diagnostic performance and clinical utility of the analyzer for these analytes.

Mass spectrometry based analytical quality assessment of serum and plasma specimens with patterns of endo- and exogenous peptides.

Background Inappropriate preanalytical sample handling is a major threat for any biomarker discovery approach. Blood specimens have a genuine proteolytic activity that leads to a time dependent decay of peptidic quality control markers (QCMs). The aim of this study was to identify QCMs for direct assessment of sample quality (DASQ) of serum and plasma specimens. Methods Serum and plasma specimens of healthy volunteers and tumor patients were spiked with two synthetic reporter peptides (exogenous QCMs) and aged under controlled conditions for up to 24 h. The proteolytic fragments of endogenous and exogenous QCMs were monitored for each time point by mass spectrometry (MS). The decay pattern of peptides was used for supervised classification of samples according to their respective preanalytical quality. Results The classification accuracy for fresh specimens (1 h) was 96% and 99% for serum and plasma specimens, respectively, when endo- and exogenous QCMs were used for the calculations. However, classification of older specimens was more difficult and overall classification accuracy decreased to 79%. Conclusions MALDI-TOF MS is a simple and robust method that can be used for DASQ of serum and plasma specimens in a high throughput manner. We propose DASQ as a fast and simple step that can be included in multicentric large-scale projects to ensure the homogeneity of sample quality.

Quality assessment of a multistage process in the case of continuous response functions from resource influences

Analytical quality assessment of a multistage process is considered in the case of continuous response functions from resource influences.

The role of 3 external quality assessment programs in assessment of analytical quality on determination of serum creatinine and urea

Objective To describe and compare the roles of 3 external quality assessment programs in assessment of analytical quality of serum creatinine and urea. Methods Research in quality management methods.Sixty-five laboratories those enrolled in the Natonal Center for Clinical Laboratories′ programs of routine chemistry external quality assessment (EQA), trueness verification (TV) for small molecular metabolites and external comparison of internal quality control (IQC) simultaneously in 2013 were selected，the performances of those laboratories of serum creatinine (crea) and urea in terms of total errors(TE), bias and CV were obtained by using the above 3 programs, and these performance were assessed against the criterion listed in the analytical quality specifications for routine analysis in clinical biochemistry (WS/T 403-2012). The failure ratio of 65 laboratories on each performance was calculated, the sensitivity of 3 external quality assessment programs in detection of analytical quality deficiency among clinical laboratories were compared. Results Only 1 laboratory failed in the 1st routine chemistry EQA in terms of TE of creatinine, failure ratio is 1.5%(1/65). Three laboratories failed in the 2nd EQA and caused a failure ratio of 4.6%(3/65). For serum urea, 3 laboratories failed in the 1st routine chemistry EQA with a failure ratio of 4.6%(3/65). Two laboratories failed in the 2nd EQA with a failure ratio of 3.1%(2/65).The failure ratios of creatinine determination in two samples in TV were 41.5%(24/65) and 21.5%(14/65) respectively, and the failure ratio of urea determination were 53.8%(36/65) and 32.3%(21/65) respectively. In the program of external comparison of IQC，the CVs of creatinine and urea determination ranged from 0.7% to 6.2% and from 1.0% to 7.2% respectively, their respective failure ratio range were 15.4%(10/65) and 40.0%(26/65). The failure ratio in routine EQA were much less than those in the other two programs, the laboratories failed in routine EQA program were all failed in trueness verification or/and the comparison of IQC programs, but not vice versa. Conclusions By participating in the programs of routine EQA, TV and comparison of IQC laboratories could assess the performances of inaccuracy, bias and imprecision. Laboratories should participate in different external quality assurance programs to detect their quality issues and get improved.（Chin J Lab Med,2014,37:357-361） Key words: Laboratories, hospital; Quality control; Creatinine; Urea; Uncertainty

Analytical quality assessment of iteratively reweighted least-squares (IRLS) method

The iteratively reweighted least-squares (IRLS) technique has been widely employed in geodetic and geophysical literature. The reliability measures are important diagnostic tools for inferring the strength of the model validation. An exact analytical method is adopted to obtain insights on how much iterative reweighting can affect the quality indicators. Theoretical analyses and numerical results show that, when the downweighting procedure is performed, (1) the precision, all kinds of dilution of precision (DOP) metrics and the minimal detectable bias (MDB) will become larger; (2) the variations of the bias-to-noise ratio (BNR) are involved, and (3) all these results coincide with those obtained by the first-order approximation method.

Interlaboratory Reproducibility and Proficiency Testing within the Human Papillomavirus Cervical Cancer Screening Program in Catalonia, Spain

In Catalonia, a screening protocol for cervical cancer, including human papillomavirus (HPV) DNA testing using the Digene Hybrid Capture 2 (HC2) assay, was implemented in 2006. In order to monitor interlaboratory reproducibility, a proficiency testing (PT) survey of the HPV samples was launched in 2008. The aim of this study was to explore the repeatability of the HC2 assay's performance. Participating laboratories provided 20 samples annually, 5 randomly chosen samples from each of the following relative light unit (RLU) intervals: <0.5, 0.5 to 0.99, 1 to 9.99, and ≥10. Kappa statistics were used to determine the agreement levels between the original and the PT readings. The nature and origin of the discrepant results were calculated by bootstrapping. A total of 946 specimens were retested. The kappa values were 0.91 for positive/negative categorical classification and 0.79 for the four RLU intervals studied. Sample retesting yielded systematically lower RLU values than the original test (P<0.005), independently of the time elapsed between the two determinations (median, 53 days), possibly due to freeze-thaw cycles. The probability for a sample to show clinically discrepant results upon retesting was a function of the RLU value; samples with RLU values in the 0.5 to 5 interval showed 10.80% probability to yield discrepant results (95% confidence interval [CI], 7.86 to 14.33) compared to 0.85% probability for samples outside this interval (95% CI, 0.17 to 1.69). Globally, the HC2 assay shows high interlaboratory concordance. We have identified differential confidence thresholds and suggested the guidelines for interlaboratory PT in the future, as analytical quality assessment of HPV DNA detection remains a central component of the screening program for cervical cancer prevention.

Application of near infrared spectroscopy for rapid detection of aflatoxin B1 in maize and barley as analytical quality assessment

The establishment of fast and non-destructive methods for the evaluation of quality and safety of raw grains is being demanded nowadays to avoid toxic substance presence. Aflatoxin B1 (AFB1) has been recognised by the International Agency of Research on Cancer as a group 1 carcinogen for animals and humans and the EU Official Journal has established action levels for AFB1 presence in all feed materials between 5 and 20 ppb. Near infrared spectroscopy (NIRS) is an excellent candidate for a rapid and low-cost method for the detection of aflatoxins in cereals. This study assesses the utility of NIRS for rapid detection of mycotoxigenic fungi as AFB1. A total of 152 samples were involved and analysed for aflatoxin content. The results of spectroscopic models developed have demonstrated that NIRS technology is an excellent alternative for fast AFB1 detection in cereals. The best predictive model to detect AFB1 in maize was obtained using standard normal variate and detrending (SNVD) as scatter correction ( r 2 = 0.80 and 0.82; SECV = 0.211 and 0.200 for grating and FT-NIRS instruments, respectively). In the case of barley, the best predictive model was developed using SNVD on the dispersive NIRS instrument ( r 2 = 0.85 and SECV = 0.176) and using spectral data as log 1/ R for FT-NIRS ( r 2 = 0.84 and SECV = 0.183).

Approach to Formulation of Nondestructive Quality Assessment Criterion of High-Strength Steel Lifting Hooks

The present investigation attempts to formulate the analytical quality assessment criteria of lifting hooks made of 4140 grade (400 °C temper) high-strength steel using linear elastic fracture mechanics (LEFM) procedures. According to the existing standard specifications, the proof load test is mandatory for the acceptance/rejection of these components. Also, there is a provision that the hooks should be checked by nondestructive testing (NDT) techniques and must be free from obvious defects, but there is no stipulation of acceptance limit of defect, if any. It is therefore not realistic and is insufficient, because sometimes tested hooks are found to fail in actual service. In the present paper, acceptance limit that is, the maximum allowable defect sizes for dynamic loads with various stress ratios are quantitatively estimated from the computed defect growth curves. The maximum allowable operating cycles for nondestructively detectable minimum defects are tabulated, from which a logical quality assessment criteria has been formulated for the assessment of the fatigue life of the hooks. This investigation is helpful for the safe operation of the hooks.

A new approach to a complete robustness test of experimental nominal conditions of chemical testing procedures for internal analytical quality assessment

The resistance presented by a particular analytical method or procedure to the generation of biased results when subjected to slight modifications in nominal experimental conditions has traditionally been known as ruggedness (from an interlaboratory trial) or robustness (from an intralaboratory study). This paper develops a protocol for a complete study of robustness, using a simple statistical technique which does not require the performance of ANOVA. The method simply consists of the establishing of a standard calibration and the creation of experimental screening designs (saturated fractioned or Plackett–Burman factorials [R.L. Plackett, J.P. Burman, Biometrika 33 (1946) 305–325]). The various stages of the test are discussed and the proposed model is applied to the real data referring to a spectrofluorimetric method of determination of lithium.

Assessment of the chemical characteristics and sources of airborne particulate matter in Santiago, Chile

Neutron activation analysis (NAA), X-ray fluorescence (XRF), proton induced X-ray emission (PIXE), atomic absorption spectrometry (AAS) and ion chromatography (IC) were used for the chemical characterization of airborne particulate matter in Santiago, Chile. The PM10 mass and elemental concentration were higher in the winter than in the summer collection period. Analytical quality assessment for NAA, XRF, PIXE, AAS and IC was performed on some samples. Correlations were found between the elements Pb−Br, Si−Ca−Fe, As−Cu−S and also between the fine mass and black carbon concentrations, which could be associated with some relevant sources.

Assessment of analytical quality in automatic flow systems

The three types of flow systems most frequently used for the automatic photometric determination of elementary parameters were systematically assessed for quality. Each type of manifold was characterized in terms of precision, sensitivity, and throughput. The uncertainty introduced by each flow unit in the manifold is assessed in standard deviation units. The systems were also tested for ruggedness of both flow injection and chemical variables. The results obtained were used as the basis for the evaluation of papers reported in literature.

Assessment of analytical quality in water analysis by flow injection methods

Flow injection methods offer a simple means for automating water analysis, and a sizeable number of applications have so far been reported. We evaluated over 200 such applications in terms of accuracy, applicability, precision, selectivity, sensitivity, determination range, and sample throughput. These parameters, which define analytical quality, were used to construct graduated scales that were employed to evaluate the real usefulness of the applications. Several conclusions are drawn as regards quality assurance.

Czechoslovakian biological certified reference materials and their use in the analytical quality assurance system in a trace element laboratory

The Trace Element Laboratory of the University of Agriculture in Prague (CSFR) participated successfully in interlaboratory experiments on the determination of the contents of trace elements in seven Czechoslovakian reference materials. Czechoslovakian certified reference material CRM 12-02-01 (Bovine liver) was used for the development of a new analytical method using the Dry Mineralizer Apion as well as in analytical quality assessment of data in the determination of Cd, Pb, and Hg contents in routinely analyzed animal tissues.