Chlorine in Distilled Water as a Source of Laboratory Error

1958 ◽  
Vol 4 (6) ◽  
pp. 513-518 ◽  
Author(s):  
Wendell T Caraway
Keyword(s):  
Uric Acid ◽  
Clinical Chemistry ◽  
Free Chlorine ◽  
Distilled Water ◽  
Color Development ◽  
Laboratory Error

Abstract Some distillation processes may result in the inadvertent contamination of distilled water with free chlorine. One part per million of free chlorine in distilled water has been shown to inhibit markedly the color development in the usual determinations of uric acid and bilirubin. The effect of free chlorine on other clinical chemistry determinations is discussed and simple tests for the detection of free chlorine in water are reviewed.

EXTRACTION OF BORON FROM CSSC REFERENCE SOILS BY HOT WATER, DILUTE CaCl2 AND MANNITOL-CaCl2 SOLUTIONS

1986 ◽  
Vol 66 (2) ◽  
pp. 377-381 ◽  
Author(s):  
P. A. SCHUPPLI
Keyword(s):  
Key Words ◽  
Soil Samples ◽  
Water Soluble ◽  
Hot Water ◽  
Distilled Water ◽  
Background Color ◽  
Color Development ◽  
Reference Soil ◽  
Highly Correlated

Soils were extracted by hot water, dilute CaCl2, and by mannitol-CaCl2 solutions and boron was determined by either azomethine-H or the curcumin method. Results were strongly method dependent; in particular results by the simplest method, mannitol-CaCl2, were generally lower and not highly correlated (r = 0.64) with those by the recommended procedure. This procedure involves extraction with hot distilled H2O (2:1 solution:soil), centrifugation, filtration, color development with azomethine-H and correction for background color. Extractable boron values by this procedure ranged from 0.1 to 1.4 mg kg−1. Background color can be further reduced by the substitution of 0.02 M CaCl2 for distilled water. Key words: CSSC reference soil samples, hot-water-soluble boron

State of the Art in Trueness and Interlaboratory Harmonization for 10 Analytes in General Clinical Chemistry

2008 ◽  
Vol 132 (5) ◽  
pp. 838-846
Author(s):  
W. Greg Miller ◽  
Gary L. Myers ◽  
Edward R. Ashwood ◽  
Anthony A. Killeen ◽  
Edward Wang ◽  
...  
Keyword(s):  
Uric Acid ◽  
State Of The Art ◽  
Clinical Chemistry ◽  
Peer Groups ◽  
Measurement Procedure ◽  
Reference Systems ◽  
Reference Measurement ◽  
Clinical Laboratories ◽  
Routine Measurement ◽  
Fresh Frozen

Abstract Context.—Harmonization and standardization of results among different clinical laboratories is necessary for clinical practice guidelines to be established. Objective.—To evaluate the state of the art in measuring 10 routine chemistry analytes. Design.—A specimen prepared as off-the-clot pooled sera and 4 conventionally prepared specimens were sent to participants in the College of American Pathologists Chemistry Survey. Analyte concentrations were assigned by reference measurement procedures. Participants.—Approximately 6000 clinical laboratories. Results.—For glucose, iron, potassium, and uric acid, more than 87.5% of peer groups meet the desirable bias goals based on biologic variability criteria. The remaining 6 analytes had less than 52% of peer groups that met the desirable bias criteria. Conclusions.—Routine measurement procedures for some analytes had acceptable traceability to reference systems. Conventionally prepared proficiency testing specimens were not adequately commutable with a fresh frozen specimen to be used to evaluate trueness of methods compared with a reference measurement procedure.

Computerized Preparation of Two-Way Analysis of Variance Control Charts for Clinical Chemistry

1972 ◽  
Vol 18 (3) ◽  
pp. 250-257 ◽  
Author(s):  
J H Riddick ◽  
Roger Flora ◽  
Quentin L Van Meter
Keyword(s):  
Quality Control ◽  
Data Analysis ◽  
Computer Program ◽  
Analysis Of Variance ◽  
Control Charts ◽  
Clinical Chemistry ◽  
Control Data ◽  
Laboratory Error ◽  
Quality Control Data

Abstract A system of quality-control data analysis by computer is described, in which two-way analysis of variance is used for partitioning sources of laboratory error into day-to-day, within-day, betweenpools and additivity variation. The partition for additivity is described in detail as to its advantages and applications. In addition, control charts based on two-way analysis of variance computations are prepared each month by computer. This computer program is designed to operate with the IBM 1800 or 1130 computers or any computer with a Fortran IV compiler. Examples are presented of use of the control charts and of tables of analysis of variance.

Thin Layer Chromatographic Method for the Detection of Uric Acid: Collaborative Study

1978 ◽  
Vol 61 (4) ◽  
pp. 903-905
Author(s):  
Joel J Thrasher ◽  
Annette Abadie
Keyword(s):  
Uric Acid ◽  
Thin Layer ◽  
Chromatographic Method ◽  
Phosphotungstic Acid ◽  
Collaborative Study ◽  
Lithium Carbonate ◽  
Improved Method ◽  
Color Development ◽  
Collaborative Tests ◽  
Layer Chromatography

Abstract A collaborative study has been completed on an improved method for the detection and confirmation of uric acid from bird and insect excreta. The proposed method involves the lithium carbonate solubilization of the suspect excreta material, followed by butanol-methanol-water-acetic acid thin layer chromatography, and trisodium phosphate-phosphotungstic acid color development. The collaborative tests resulted in 100% detection of uric acid standard at the 50 ng level and 75% detection at the 20–25 ng level. No false positives were reported during tests of compounds similar to uric acid. The proposed method has been adopted official first action; the present official final action method, 44.161, will be retained for screening purposes.

Measurement and Standard Reference Materials in Clinical Chemistry

1968 ◽  
Vol 14 (10) ◽  
pp. 929-943 ◽  
Author(s):  
Donald S Young ◽  
Thomas W Mears
Keyword(s):  
Uric Acid ◽  
Reference Materials ◽  
Measurement System ◽  
High Purity ◽  
Clinical Chemistry ◽  
Standard Reference Materials ◽  
National Bureau ◽  
Additional Component ◽  
Clinical Laboratories ◽  
Chemical Measurements

Abstract The concepts of the measurement system based upon four parameters—length (meter), mass (kilogram), time (second), and temperature (kelvin)—are developed. The proper daily operation of an analytic laboratory depends upon these basic measurements and others derived from them, e.g., the liter. An additional component of chemical measurement which directly influences accuracy is the purity of the standards and reagents employed. The standard reference materials program of the National Bureau of Standards provides a central source of guaranteed high-purity reference materials which are available to all. The reliability of chemical measurements should increase as new standard reference materials such as cholesterol, uric acid, urea, and creatinine are utilized to standardize methods and to calibrate instruments in the clinical laboratories of this country.

scholarly journals Measurements for 8 Common Analytes in Native Sera Identify Inadequate Standardization among 6 Routine Laboratory Assays

2014 ◽  
Vol 60 (6) ◽  
pp. 855-863 ◽  
Author(s):  
Hedwig C M Stepman ◽  
Ulla Tiikkainen ◽  
Dietmar Stöckl ◽  
Hubert W Vesper ◽  
Selvin H Edwards ◽  
...  
Keyword(s):  
Uric Acid ◽  
Ldl Cholesterol ◽  
Peer Group ◽  
Clinical Chemistry ◽  
Total Error ◽  
Random Access ◽  
Reference Method ◽  
Hdl Cholesterol ◽  
Serum Samples ◽  
Fresh Frozen

Abstract BACKGROUND External quality assessment (EQA) with commutable samples is essential for assessing the quality of assays performed by laboratories, particularly when the emphasis is on their standardization status and interchangeability of results. METHODS We used a panel of 20 fresh-frozen single-donation serum samples to assess assays for the measurement of creatinine, glucose, phosphate, uric acid, total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. The commercial random access platforms included: Abbott Architect, Beckman Coulter AU, Ortho Vitros, Roche Cobas, Siemens Advia, and Thermo Scientific Konelab. The assessment was done at the peer group level and by comparison against the all-method trimmed mean or reference method values, where available. The considered quality indicators were intraassay imprecision, combined imprecision (including sample–matrix interference), bias, and total error. Fail/pass decisions were based on limits reflecting state-of-the-art performance, but also limits related to biological variation. RESULTS Most assays showed excellent peer performance attributes, except for HDL- and LDL cholesterol. Cases in which individual assays had biases exceeding the used limits were the Siemens Advia creatinine (−4.2%), Ortho Vitros phosphate (8.9%), Beckman Coulter AU triglycerides (5.4%), and Thermo Scientific Konelab uric acid (6.4%), which lead to considerable interassay discrepancies. Additionally, large laboratory effects were observed that caused interlaboratory differences of >30%. CONCLUSIONS The design of the EQA study was well suited for monitoring different quality attributes of assays performed in daily laboratory practice. There is a need for improvement, even for simple clinical chemistry analytes. In particular, the interchangeability of results remains jeopardized both by assay standardization issues and individual laboratory effects.

Rotavirus survival in conventionally treated drinking water

1984 ◽  
Vol 30 (5) ◽  
pp. 653-656 ◽  
Author(s):  
S. A. Sattar ◽  
R. A. Raphael ◽  
V. S. Springthorpe
Keyword(s):  
Drinking Water ◽  
Treatment Plant ◽  
Free Chlorine ◽  
Virus Titre ◽  
Distilled Water ◽  
Virus Suspension ◽  
Term Survival ◽  
Tryptose Phosphate Broth ◽  
Treated Drinking Water

Samples of conventionally treated drinking water collected either as effluent (PE) at a treatment plant or out of a tap (TW) in our laboratory were seeded with simian rotavirus SA-11, which closely resembles rotavirus of human origin. The virus, grown in MA-104 cells, was suspended either in distilled water, Earle's balanced salt solution (EBSS), or tryptose phosphate broth (TPB), and added to the water samples to a final concentration of 5.7 × 103 plaque-forming units (PFU) per millilitre. After a contact time of 1 h at 22 °C, the samples were diluted and plaque assayed. There was no significant reduction in the virus titre in samples of TW (<0.05 mg/L free chlorine). The titre also remained almost the same in PE (0.75 mg/L free chlorine) when EBSS or TPB was used for virus suspension. There was, however, nearly a 1 log10 loss in the titre of the virus when it was suspended in distilled water before the contamination of PE. To study the long-term survival of the rotavirus in TW, the inoculated samples (5.0 × 104 PFU/mL) were held at either 4 or 20 °C in the dark and tested over a period of 64 days. At 20 °C it took 64 days to reduce the virus titre by 2 log10, whereas at 4 °C the virus titre dropped only 0.7 log10 during the same period. Rotaviruses could, therefore, survive well enough in conventionally treated drinking water to make it a possible vehicle for their transmission.

scholarly journals Temperature impact on monochloramine, free ammonia, and free chlorine indophenol methods

2020 ◽  
Author(s):  
Thomas E. Waters ◽  
Matthew T. Alexander ◽  
David G. Wahman
Keyword(s):  
Environmental Protection Agency ◽  
Measurement Errors ◽  
Method Development ◽  
Reaction Times ◽  
The United States ◽  
Free Chlorine ◽  
Free Ammonia ◽  
Color Development ◽  
Temperature Impact ◽  
Development Temperature

Abstract A commercial colorimetric indophenol (IP) method is used for determining monochloramine (NH2Cl) concentrations for process control in chloraminated public water systems and chloramine–related research. The NH2Cl – IP method excludes some quality control procedures typically included in drinking water methods and is not approved by the United States Environmental Protection Agency (U.S. EPA) for compliance monitoring. Therefore, the authors developed and validated a more complete NH2Cl–IP method, building on the commercial technique, as a candidate for future approval. During method development, temperature impact on color development was investigated. Color development time increased as temperature decreased. Below 20 °C, times needed for full color development were greater than those reported in the commercial method, reaching nearly three times longer at 5 °C. This observed temperature dependence also applies to free ammonia and free chlorine indophenol methods. To avoid measurement errors of samples analyzed below 20 °C, use of reaction times determined in this study is recommended for these indophenol methods.

scholarly journals The EuBIVAS: Within- and Between-Subject Biological Variation Data for Electrolytes, Lipids, Urea, Uric Acid, Total Protein, Total Bilirubin, Direct Bilirubin, and Glucose

2018 ◽  
Vol 64 (9) ◽  
pp. 1380-1393 ◽  
Author(s):  
Aasne K Aarsand ◽  
Jorge Díaz-Garzón ◽  
Pilar Fernandez-Calle ◽  
Elena Guerra ◽  
Massimo Locatelli ◽  
...  
Keyword(s):  
Uric Acid ◽  
Total Protein ◽  
Total Bilirubin ◽  
Service Providers ◽  
Clinical Chemistry ◽  
Hdl Cholesterol ◽  
Biological Variation ◽  
Direct Bilirubin ◽  
European Federation ◽  
Variation Data

Abstract BACKGROUND The European Federation of Clinical Chemistry and Laboratory Medicine European Biological Variation Study (EuBIVAS) has been established to deliver rigorously determined data describing biological variation (BV) of clinically important measurands. Here, EuBIVAS-based BV estimates of serum electrolytes, lipids, urea, uric acid, total protein, total bilirubin, direct bilirubin, and glucose, as well as their associated analytical performance specifications (APSs), are presented. METHOD Samples were drawn from 91 healthy individuals (38 male, 53 female; age range, 21–69 years) for 10 consecutive weeks at 6 European laboratories. Samples were stored at −80 °C before duplicate analysis of all samples on an ADVIA 2400 (Siemens Healthineers). Outlier and homogeneity analyses were performed, followed by CV-ANOVA on trend-corrected data, when relevant, to determine BV estimates with CIs. RESULTS The within-subject BV (CVI) estimates of all measurands, except for urea and LDL cholesterol, were lower than estimates available in an online BV database, with differences being most pronounced for HDL cholesterol, glucose, and direct bilirubin. Significant differences in CVI for men and women/women &lt;50 years of age were evident for uric acid, triglycerides, and urea. The CVA obtained for sodium and magnesium exceeded the EuBIVAS-based APS for imprecision. CONCLUSIONS The EuBIVAS, which is fully compliant with the recently published Biological Variation Data Critical Appraisal Checklist, has produced well-characterized, high-quality BV estimates utilizing a stringent experimental protocol. These new reference data deliver revised and more exacting APS and reference change values for commonly used clinically important measurands, thus having direct relevance to diagnostics manufacturers, service providers, clinical users, and ultimately patients.

Effect of the Use of a Neutralizing Step after Antimicrobial Application on Microbial Counts during Challenge Studies for Orange Disinfection

2013 ◽  
Vol 76 (2) ◽  
pp. 328-332 ◽  
Author(s):  
N. E. MARTÍNEZ-GONZÁLES ◽  
C. MARTÍNEZ-CÁRDENAS ◽  
L. MARTÍNEZ-CHÁVEZ ◽  
N. E. RAMOS-PÉREZ ◽  
T. M. TAYLOR ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Tap Water ◽  
Residual Activity ◽  
Time Lapse ◽  
Antimicrobial Treatment ◽  
Free Chlorine ◽  
Hot Water ◽  
Distilled Water ◽  
Peptone Water ◽  
Accuracy Of Results

The effects of using a neutralizer after applying antimicrobial treatments and the effect of time lapse between treatment application and subsequent recovery and enumeration of Escherichia coli O157:H7 and Salmonella were investigated in Valencia oranges. Inoculated oranges surfaces were washed with distilled water for 15 s and then sprayed with a solution containing 200 mg/liter sodium hypochlorite (pH 6.5) for 15 s; they were then dipped in L-lactic acid (2.0% at 55°C) for 1 min or in distilled water at 80°C for 1 min. Posttreatment, oranges were divided into two groups. In the first group, oranges were dipped in neutralization treatment: 270 ml of buffered peptone water for 2 min for lactic acid–treated oranges, 270 ml of Dey-Engley broth for 2 min for chlorine-treated oranges, or 3.7 liters of tap water (25°C) for 10 s for hot water–treated oranges. The second group of treated oranges was not subjected to any neutralizer. All oranges then were kept at room temperature (average 26.2°C) and sampled at 0, 7.5, and 15 min for enumeration of surviving Salmonella and E. coli O157:H7. The orange surface (30 cm2) was excised for pathogen enumeration. The presence of free chlorine and changes in pH and temperature on the orange surface were determined in uninoculated, treated oranges. Free chlorine was detected on oranges after treatment; the change in temperature of orange surfaces was greater during treatment with hot water than with lactic acid. Nevertheless, pathogen enumeration did not show any impact of neutralizer use on the residual activity of antimicrobials or any impact of the time elapsed between antimicrobial treatment and recovery of bacterial pathogens from inoculated oranges (P ≥ 0.05). The results of this study indicate that the lack of a neutralizing step before enumeration of pathogens is not likely to affect the accuracy of results during challenge studies to test pathogen reduction strategies on oranges.

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