Br, Rb, Zn, Fe, Se and K in blood of colorectal patients by INAA and PIXE.

A preliminary study was conducted on blood samples and blood fractions of 11 colorectal patients and 10 healthy subjects (controls) in Belgium, in order to determine the concentration of some vital trace elements. Two non destructive analytical methods were used for the determination: INAA and PIXE. The agreement between PIXE and INAA was within about +/- 10% for plasma, but for Rb, Se and Fe in whole blood and red cells a difference of +/- 20% was noted; part of the discrepancy may be due to self absorption problems in PIXE, and for Rb, spectral interferences also may have contributed. The precision of the INAA method for the elements studied was found to be +/- 3% for whole blood and red cells and +/- 5% for plasma; the accuracy for Br, Rb and Zn was better than +/- 10% and +/- 17% for Se. The ratios of the concentrations in whole blood to red cells and whole blood to plasma were not significantly different for normals and cancer cases and, therefore, in future studies analysis of whole blood only may be sufficient. The mean values for Br, Rb, Br/Rb ratio, K, Fe and Se were significantly lower for cancer cases than for healthy individuals, and this might be applicable as an additional parameter for differentiating normals from malignant cases.

Bismuth in human serum: reference interval and concentrations after intake of a therapeutic dose of colloidal bismuth subcitrate.

A sensitive method for the determination of the bismuth concentration in human serum is described. Analyses were carried out by inductively coupled plasma-mass spectrometry (ICP-MS), after a simple dilution of the samples with nitric acid. The detection limit of the applied method is 0.007 microgram/l whereas relative standard deviations varied from 5.7 to 13.6%. Determination of reference values in human serum of healthy adults gave a range from < 0.007 to 0.067 microgram/l (19 persons). Bismuth concentrations in serum were also measured before, during and after the intake of therapeutic doses of colloidal bismuth subcitrate (CBS). About 1.5-2 h after the intake of one tablet of CBS, the bismuth concentration in serum was found to have increased 51-1483 times (two apparently healthy volunteers and six hospitalized patients), showing that the serum bismuth concentrations can increase by several orders of magnitude during the intake of CBS. During the intake of four tablets of CBS per day by two apparently healthy volunteers, bismuth concentrations in serum after an overnight fast were found to be, respectively, 5.56 and 8.1 micrograms/l on day 15 and 4.28 and 13.6 micrograms/l on day 29. After stopping the therapy, the concentration of bismuth in serum slowly returned towards normal over a period of months.

Determination of tin in human blood serum by radiochemical neutron activation analysis.

A method was developed for the determination of tin in human serum by radiochemical neutron activation analysis, using the long-lived radioisotope Sn(T1/2 = 115.09 days). This radioisotope decays to a daughter isotope 113mIn, the most suitable nuclide for counting (T1/2 = 1.658 h, gamma-ray of 391.7 keV). Experience showed that, with the exception of the serum samples with the lowest tin levels, in the experimental conditions of the present study tin could mostly also be determined by using its radioisotope 117mSn(T1/2 = 13.61 days, gamma-ray of 158.5 keV). Samples were collected and prepared by using the procedure elaborated by the authors, which proved its effectiveness in preventing significant sample contamination on several occasions. Because samples had to be irradiated at 10(14) n.cm-2.s-1, dry ashing was necessary. After irradiation, tin was separated by solvent extraction of tin(IV) iodide from a sulfuric acid-ammonium iodide solution with toluene. The dry ashing and solvent extraction steps were exhaustively tested by means of radioactive tracer experiments whereas the accuracy and precision of the analytical method were thoroughly checked by analyzing biological reference materials (Bowen's kale powder, the NBS' bovine liver, the NBS' nonfat milk powder, and the "second-generation" biological reference material--freeze-dried human serum--for trace element determinations, developed by the authors).(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of strontium in human serum by inductively coupled plasma mass spectrometry and neutron activation analysis: A comparison.

Strontium has been determined in a human serum reference material by ICP-MS and by NAA. By ICP-MS, results for (88)Sr and (86)Sr in both 10- and 5-fold diluted serum were in good agreement. For (88)Sr the precision was better than 3% and the detection limit was 0.05 mug/l. under the conditions used. The results were 25.5 mug/l. in the liquid serum or 0.281 mug/g in the lyophilized reference material. In the NAA the (87m)Sr produced was radiochemically separated by extraction with oxine in chloroform. The precision was about 10% and the detection limit 0.02-0.05 mug/g.

Determination of mercury in human serum and packed blood cells by neutron activation analysis.

A method is described for the determination of mercury in human blood serum and packed blood cells employing neutron activation analysis. Great attention was devoted to the collection and manipulation of the samples. The accuracy and precision of the method were tested by analyzing biological reference materials and by comparing the concentrations measured in a number of serum samples to those obtained by another, independent technique (cold vapor atomic absorption spectrometry) in the same samples. The article reports the levels measured in blood serum and packed blood cells samples from 15 adult volunteers, as well as the figures determined in a "second-generation" biological reference material (freeze-dried human serum), prepared and conditioned at the University of Ghent.

Accuracy of biological trace-element determinations.

Mounting evidence suggests that the accuracy of much of the published information on trace-element concentrations in biological matrices leaves much to be desired. Potential sources of error are: (a) inadequate sample collection and preparation (sampling errors); and (b) inaccuracies at the moment of the measurement (measurement errors). Probably much of what has been maintained on trace elements in human health and disease in the past will have to be revised in the future.

Alpha 1-antitrypsin in pancreatitis.

A possible relationship between alpha 1-antitrypsin deficiency and pancreatitis was studied. Pi phenotype distribution in a group of 90 patients with proven pancreatitis was compared to a control group of 549 randomly selected blood donors. No significant differences were found between the patient group and the controls, nor between acute and chronic forms of pancreatitis. It is concluded that alpha 1-antitrypsin phenotype does not play an important role in pancreatic disease.

Serum molybdenum in diseases of the liver and biliary system.

We determined the serum molybdenum concentration by neutron activation analysis in apparently healthy subjects and in patients with diseases of the liver and biliary system. The level was found to be markedly elevated in the initial phase of acute viral hepatitis (mean +/- S.D. 3.10 +/- 1.46 ng/ml vs. 0.55 +/- 0.21 in controls) and to return to normal during convalescence, in parallel with the liver function tests. The most significant correlations were found between the serum molybdenum concentration and the serum levels of GOT ( r = 0.710, p less than 0.001) and GPT (r = 0.683, p less than 0.001). Besides, the serum molybdenum level (mean +/- S.D.) was observed to be definitely increased in patients with HBsAg-positive chronic active hepatitis (0.97 +/- 0.49 ng/ml), HBsAg-positive liver cirrhosis (1.01 +/- 0.50), alcoholic liver disease (1.32 +/- 0.56), liver metastases (1.40 +/-0.39), gallstones (1.28 +/- 0.38), tumors of the gallbladder or extrahepatic bile ducts (1.64 +/- 0.44), and carcinoma of the head of the pancreas (1.61 +/- 0.91). Finally, the serum molybdenum level was found to be raised in two patients with primary biliary cirrhosis and in two out of four patients with drug-induced liver injury. The etiologic mechanism and the clinical importance of the observed abnormality remain to be established. Our study enlarges the existing information concerning the disorders of trace element metabolism in liver diseases.

Determination of molybdenum in human serum by neutron activation analysis.

Several investigators have reported serum molybdenum determinations in healthy humans. However, their results diverge quite widely. We determined the element by neutron activation analysis in 30 individuals. We found a mean value of 0.58 ng/ml, a standard deviation of 0.21 ng/ml and a range of 0.28--1.17 ng/ml.