BACKGROUND: The urinary iodine micromethod (UIMM) is a modification of the conventional method and its performance needs evaluation. METHODS: UIMM performance was evaluated using the method validation and 2008 Iodine Deficiency Disorders survey data obtained from four urinary iodine (UI) laboratories. Method acceptability tests and Sigma quality metrics were determined using total allowable errors (TEas) set by two external quality assurance (EQA) providers. RESULTS: UIMM obeyed various method acceptability test criteria with some discrepancies at low concentrations. Method validation data calculated against the UI Quality Program (TUIQP) TEas showed that the Sigma metrics were at 2.75, 1.80, and 3.80 for 51+/-15.50 microg/L, 108+/-32.40 microg/L, and 149+/-38.60 microg/L UI, respectively. External quality control (EQC) data showed that the performance of the laboratories was within Sigma metrics of 0.85-1.12, 1.57-4.36, and 1.46-4.98 at 46.91+/-7.05 microg/L, 135.14+/-13.53 microg/L, and 238.58+/-17.90 microg/L, respectively. No laboratory showed a calculated total error (TEcalc) Humans ; Iodine/*urine ; Laboratories/standards ; Quality Control ; Spectrophotometry/*standards ; Urinalysis/*standards

Arsenic ; urine ; Freeze Drying ; standards ; Humans ; Reference Standards ; Urinalysis ; methods ; standards

OBJECTIVETo develop the certified reference material of mercury in lyophilized human urine.

METHODSHuman urine samples from normal level mercury districts were filtered, homogenized, dispensed, lyophilized and radio-sterilized. Homogeneity test, stability inspection and certification were conducted using a atom fluorescence spectrophotometric method. The physical and chemical stability of the certified reference material were assessed for 18 months. The certified values are based on analysis made by three independent laboratories.

RESULTSThe certified values are as follows: low level was (35.6 ± 2.1) µg/L, high level was (50.5 ± 3.0) µg/L.

CONCLUSIONThe certified reference material of mercury in lyophilized human urine in this research reached the national certified reference material requirements and could be used for the quality control.

Freeze Drying ; standards ; Humans ; Mercury ; urine ; Reference Standards ; Spectrometry, Fluorescence ; Urinalysis ; standards

OBJECTIVETo evaluate the uncertainty of measurement result of urinary fluoride and to provide quality assurance for determinations.

METHODThe investigation was conducted, according with principles and methods for uncertainty evaluation.

RESULTSThe uncertainty of the combined standard of present method was 2.86 %. For the sample containing 4.47 mg/L urinary fluoride, the expanded uncertainty was 0.26 mg/L.

CONCLUSIONThe uncertainty of the present method was mainly from the sample repeatability, the preparation of standard solution, the linearity of the calibration curve and instruments and so on.

Fluorides ; urine ; Ion-Selective Electrodes ; standards ; Quality Control ; Uncertainty ; Urinalysis ; methods

Acute kidney injury (AKI) and chronic kidney disease (CKD) are major health problems. Urinary biomarkers have both diagnostic and prognostic utility in AKI and CKD. However, how biomarker excretion rates should be reported, especially whether they should be normalised to urinary creatinine concentration (uCr), is controversial. Some studies suggest that normalisation to uCr may be inappropriate at times, as urinary creatinine excretion rate may vary greatly, depending on the situation. Notably, recent studies suggest that while normalisation of values to UCr may be valid for the evaluation of CKD and prediction of AKI sequelae and occurrences, it could be inappropriate for the diagnosis of AKI, or in the presence of certain acute kidney disease states.
Acute Kidney Injury ; urine ; Biomarkers ; urine ; Creatinine ; urine ; Glomerular Filtration Rate ; Humans ; Kidney ; physiopathology ; Nephrology ; methods ; standards ; Renal Insufficiency, Chronic ; urine ; Treatment Outcome ; Urinalysis ; standards