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Objective:To develop a standard method for determination of iodine in serum by inductively coupled plasma mass spectrometry (ICP-MS).Methods:A direct dilution sampling-ICP-MS method for measuring iodine in serum was developed with 2.0 g/L ascorbic acid-1.0 g/L ammonium chloride-0.10% ethanolamine-1.0% ethanol as diluent; the standard solutions and the serum samples were all diluted in a ratio of 1 : 19 (sample : diluent) before testing with Re as internal standard element. Methodological evaluation of a new method was done through standard curve linearity, sample detection limit, precision and accuracy in determining serum iodine. And the results were compared with the results determined by current standard method for determination of iodine in serum [arsenic-cerium catalytic spectrophotometry, hereinafter referred to as the standard method (WS/T 572-2017)].Results:The following data were obtained by testing the method in six laboratories. The linear range of the calibration curve was 0 - 300 μg/L and the linear correlative coefficients were 0.999 9 - 1.000 0 ( n = 70). The detection limit for serum iodine was 0.2 to 1.3 μg/L (0.20 ml of serum was tested). Precision: the average intra assay coefficient of variation ( CV) was 0.6% with a range of 0.2% - 1.6% when measuring 31 serum samples; the average inter assay CV was 1.3% with a range of 0.3% - 2.4% when measuring 34 serum samples. Accuracy: the average recovery was 100.3% with a range of 93.9% - 105.6% when measuring 36 serum samples. No significant difference was found between the results of the 116 serum samples determined by the new method and the standard method ( P > 0.05). Conclusions:The new method has a good standard curve linearity, high sensitivity, good precision, accuracy and is easy to be used and quickly to be analyzed of the test results, and is suitable for widely application in determining serum iodine.
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Objective To determine serum iodine by inductively coupled plasma mass spectrometry (ICP-MS).Methods ICP-MS was used to determine iodine content directly by pretreatment method of diluting serum samples and standard series with diluent.The method was tested from correlation coefficient of standard curve,detection limit,precision,accuracy,etc.Results When the concentration of iodine in serum ranged from 0 to 300 μg/L,the linear correlation coefficient with the iodine ion counts determined by the instrument was 0.999 8 to 1.000 0 (n =6);the detection limit of iodine in serum was 1.24 μg/L;the relative standard deviation (RSD) ranged from 0.5％ to 1.5％ and from 0.3％ to 1.4％ for the intra-and inter-batch precision tests of seven different serum samples,respectively;the recovery rate of 7 serum samples with iodine content 40-230 μg/L ranged from 93.4％ to 109.2％,and the total average recovery rate was 102.4％.Conclusions Serum samples need not be pretreated before digestion,and can be directly injected after dilution with diluent without using highly toxic substances.The detection process is automatic,sensitive,precise,accurate and suitable for rapid quantitative determination of serum iodine content.
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Objective To understand the stability of iodine content in potassium iodide iodized salt and potassium iodate iodized salt during production.Methods The sodium sulfate type brine well rock salt and calcium salt brine well rock salt as raw material were used to produce potassium iodide salt and potassium iodate salt by different iodization methods of before and after fluid bed dryer and then the loss of iodine during production was measured,meanwhile iodine content of powder salt was determined.According to the "Belt Delivery Sampling of Sampling Methods of the Main Products in the Salt Industry" (GB/T 8616-2001),25 standard salt samples and 6-24 powder salt samples were collected in the same batch.The salt iodine content was determined by oxidationreduction titration and direct titration of the "General Test Method in Salt Industry-Determination of Iodine" (GB/T 13025.7-2012).Results For the sodium sulfate type brine well rock salt,there was no statistical difference in iodine loss rate between potassium iodide salt and potassium iodate salt (16.55％ vs.19.60％,x2 =0.01,P ＞ 0.05) by iodization of before fluid bed dryer.The iodine loss rate of potassium iodide salt was 2.17％ and the iodine loss of potassium iodate salt was undetectable and there was no statistical difference between the two (x2 =2.19,P ＞ 0.05)by iodization of after fluid bed dryer.For calcium salt brine well rock salt,the iodine loss rate of potassium iodide was less than that of potassium iodate (20.60％ vs.39.75％,x2 =8.70,P ＜ 0.05) by iodization of before fluid bed dryer and neither of them was lost by iodization of after fluid bed dryer.Conclusions For both sodium sulfate type brine well rock salt and calcium salt brine well rock salt,the iodine loss of iodide iodized salt is not higher than that of potassium iodate during iodization of before or after fluid bed dryer.Since the iodine loss during iodization of before fluid bed dryer is significantly higher than that after fluid bed dryer,adopting iodization of after fluid bed dryer to produce iodized salt should be recommended.
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Objective To investigate the correlation of alkal ine phosphatase(ALP) and isozymes with renal disease.Methods In 1997-03~2003-05 the activity of ALP was determined b y biochemical automatic analyzer in Heilongjiang Province Hospital.The activity of ALP isozymes were determined by polyacrylamide disc gel electrophoresis and s canning measurement.Results The samples from patients with renal disease were divid ed into glomerular injury group,renal tubular injury group and severe widespread damage group based on the pathological changes.The activity of ALPs in urine i n the glomerular injury group and renal tubular injury group were significantly different from those in the control group (P0.05).Conclusion Isozymes of ALP in urine can be a useful marker for different renal segments injury.