scholarly journals Sweat chloride assay by inductively coupled plasma mass spectrometry: a confirmation test for cystic fibrosis diagnosis

2020 ◽  
Vol 412 (25) ◽  
pp. 6909-6916
Author(s):  
Antonella Marvelli ◽  
Beatrice Campi ◽  
Gianfranco Mergni ◽  
Maria Elisa Di Cicco ◽  
Paola Turini ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cystic Fibrosis ◽  
Inductively Coupled Plasma ◽  
Chloride Concentration ◽  
Inductively Coupled ◽  
Sweat Chloride ◽  
Icp Ms ◽  
Relative Standard ◽  
Plasma Mass Spectrometry ◽  
Current Guidelines

Abstract The current guidelines for sweat chloride analysis identify the procedures for sweat collection, but not for chloride assay, which is usually performed by methods originally not aiming at the low concentrations of chloride found in sweat. To overcome this limitation, we set up, characterized, and adopted an original inductively coupled plasma mass spectrometry (ICP-MS) method for sweat chloride determination, which was designed for its easy use in a clinical laboratory. The method was linear in the range 8.5E−3 to 272.0E−3 mM, precision exhibited a relative standard deviation < 6%, and accuracy was in the range 99.7–103.8%. Limit of blank, limit of detection, and limit of quantitation were 2.1 mM, 3.2 mM, and 7.0 mM, respectively, which correspond to real concentrations injected into the mass spectrometer of 3.9E−3 mM for LOD and 8.5E−3 mM for LOQ. At first, the method was tested on 50 healthy volunteers who exhibited a mean chloride concentration of 15.7 mM (25–75th percentile 10.1–19.3 mM, range 2.8–37.4 mM); then, it was used to investigate two patients with suspected cystic fibrosis, who exhibited sweat chloride values of 65.6 mM and 81.2 mM, respectively. Moreover, the method was cross-validated by assaying 50 samples with chloride concentration values in the range 10–131 mM, by both ICP-MS and coulometric titration, which is the technology officially used in Tuscany for cystic fibrosis newborn screening. The reference analytical performances and the relatively low cost of ICP-MS, accompanied by the advantageous cost of a single sweat chloride assay, make this technology the best candidate to provide a top reference method for the quantification of chloride in sweat. The method that we propose was optimized and validated for sweat samples ≥ 75 mg, which is the minimum amount requested by the international protocols. However, the method sensitivity and, in addition, the possibility to reduce the sample dilution factor, make possible the quantification of chloride even in samples weighting < 75 mg that are discarded according to the current guidelines.

scholarly journals Determination of Arsenic, Cadmium, Mercury, and Lead by Inductively Coupled Plasma/Mass Spectrometry in Foods after Pressure Digestion: NMKL Interlaboratory Study

2007 ◽  
Vol 90 (3) ◽  
pp. 844-856 ◽  
Author(s):  
Kaare Julshamn ◽  
Amund Maage ◽  
Hilde Skaar Norli ◽  
Karl H Grobecker ◽  
Lars Jorhem ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Method Performance ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Plasma Mass Spectrometry ◽  
Standard Deviations

Abstract Thirteen laboratories participated in an interlaboratory method performance (collaborative) study on a method for the determination of arsenic, cadmium, mercury, and lead by inductively coupled plasma/mass spectrometry (ICP/MS) after pressure digestion including the microwave heating technique. Prior to the study, the laboratories were able to practice on samples with defined element levels (pretrial test). The method was tested on a total of 7 foodstuffs: carrot puree, fish muscle, mushroom, graham flour, simulated diet, scampi, and mussel powder. The elemental concentrations in mg/kg dry matter (dm) ranged from 0.0621.4 for As, 0.0328.3 for Cd, 0.040.6 for Hg, and 0.012.4 for Pb. The materials used in the study were presented to the participants as blind duplicates, and the participants were asked to perform single determinations on each sample. The repeatability relative standard deviations (RSDr) for As ranged from 3.8 to 24%, for Cd from 2.6 to 6.9%, for Hg from 4.8 to 8.3%, and for Pb from 2.9 to 27%. The reproducibility relative standard deviations (RSDR) for As ranged from 9.0 to 28%, for Cd from 2.8 to 18%, for Hg from 9.9 to 24%, and for Pb from 8.0 to 50%. The HorRat values were less than 1.5 for all test samples, except for the determination of Pb in wheat flour at a level close to the limit of quantitation (0.01 mg/kg dm). The study showed that the ICP/MS method is satisfactory as a standard method for elemental determinations in foodstuffs.

Determination of Trace Elements in Water by Inductively Coupled Plasma–Mass Spectrometry: Collaborative Study

1994 ◽  
Vol 77 (4) ◽  
pp. 1004-1023 ◽  
Author(s):  
J E Longbottom ◽  
T D Martin ◽  
K W Edgell ◽  
S E Long ◽  
M R Plantz ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Acid Digestion ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Nitric Acid Digestion ◽  
Plasma Mass Spectrometry

Abstract A joint U.S. Environmental Protection Agency (U.S. EPA)—AOAC interlaboratory method validation study was conducted on U.S. EPA method 200.8, Determination of Trace Elements in Waters and Wastes by Inductively Coupled Plasma–Mass Spectrometry. The purpose of the study was to determine and compare the mean recovery and precision of the inductively coupled plasma–mass spectrometry (ICP–MS) analyses for 20 trace elements in reagent water, drinking water, and groundwater. The formal study was based on Youden’s nonreplicate plan for collaborative tests of analytical methods. The test waters were spiked with the 20 trace elements at 6 concentration levels in the 0.8–200 μg/L range, prepared as 3 Youden pairs. Thirteen collaborators spiked 100 mL aliquots of the test waters, acidified them with 1 mL concentrated HNO3 and 0.5 mL concentrated HCl, reduced the volume to 20 mL by heating in an open beaker at 85°C, refluxed them for 30 min at 95°C, and diluted them to 50 mL. After centrifuging or settling the samples, a 20 mL portion of the supernatant was diluted to 50 mL and analyzed by ICP–MS. Related experiments evaluated the method performance in wastewater and wastewater digestate at a single concentration pair, and an alternative nitric acid digestion procedure. Mean recoveries for reagent water, drinking water, and groundwater were generally 95–105% with between-laboratory relative standard deviations about 4–8%. The method also worked well with wastewaters and digestate, with between-laboratory relative standard deviations averaging 8% and recoveries averaging 100%. Recoveries of silver, however, were low in all matrixes at concentrations over 100 μg/L. The nitric acid digestion procedure was comparable in accuracy and precision to the mixed-acid digestion in U.S. EPA method 200.8. The method was adopted first action by AOAC INTERNATIONAL.

scholarly journals Determination of Metals in Composite Diet Samples by Inductively Coupled Plasma-Mass Spectrometry

2003 ◽  
Vol 86 (2) ◽  
pp. 439-448 ◽  
Author(s):  
Lisa Jo Melnyk ◽  
Jeffrey N Morgan ◽  
Reshan Fernando ◽  
Edo D Pellizzari ◽  
Olujide Akinbo
Keyword(s):  
Mass Spectrometry ◽  
Atmospheric Pressure ◽  
Inductively Coupled Plasma ◽  
Microwave Digestion ◽  
Standard Reference Materials ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Plasma Mass Spectrometry

Abstract A study was conducted to evaluate the applicability of inductively coupled plasma-mass spectrometry (ICP-MS) techniques for determination of metals in composite diets. Aluminum, cadmium, chromium, copper, lead, manganese, nickel, vanadium, and zinc were determined by this method. Atmospheric pressure microwave digestion was used to solubilize analytes in homogenized composite diet samples, and this procedure was followed by ICP-MS analysis. Recovery of certified elements from standard reference materials ranged from 92 to 119% with relative standard deviations (RSDs) of 0.4–1.9%. Recovery of elements from fortified composite diet samples ranged from 75 to 129% with RSDs of 0–11.3%. Limits of detection ranged from 1 to 1700 ng/g; high values were due to significant amounts of certain elements naturally present in composite diets. Results of this study demonstrate that low-resolution quadrupole-based ICP-MS provides precise and accurate measurements of the elements tested in composite diet samples.

scholarly journals Comparison of Ion-Selective Electrode and Inductively Coupled Plasma-Mass Spectrometry to Determine Iodine in Milk-Based Nutritional Products

2008 ◽  
Vol 91 (6) ◽  
pp. 1397-1401 ◽  
Author(s):  
Daniel Hammer ◽  
Daniel Andrey
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Certified Reference Materials ◽  
Ion Selective Electrode ◽  
Good Precision ◽  
Selective Electrode ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Plasma Mass Spectrometry

Abstract The performances of 2 official methods for iodine analysis based on inductively coupled plasma-mass spectrometry (ICP-MS) and the ion-selective electrode (ISE) method were compared for milk-based products. The aim of the study was to determine the performance characteristics of both methods to check the labeled concentration of iodine. Good precision was found for both methods with highest relative standard deviation of repeatability (RSDr) at 2.3 and 2.7 for ISE and ICP-MS, respectively. Intermediate reproducibility (RSDiR), single laboratory within 6 different days, was also good with the highest values at 7.3 and 8 by ISE and ICP-MS, respectively. Measurement uncertainty was estimated based on the RSDiR data, and it was concluded that both methods were capable of determining iodine concentrations within an uncertainty below 20. The accuracy of the methods was determined by analyzing certified reference materials, in-house proficiency test samples, and commercial products. Both methods returned similar results when applied on freshly opened samples. In samples that had been opened and kept exposed to air during storage, ISE returned lower iodine concentrations than ICP-MS. In commercial samples, the linear regression between both methods was ISE 0.95 ICP-MS 0.060 for freshly opened samples and ISE 0.85 ICP-MS 0.069 for samples exposed to air. The tendency of ISE to return lower results than ICP-MS is explained by the fact that ISE is sensitive to iodide but does not measure iodine that may be bound organically to the matrix. This seems to be more pronounced in samples that were stored longer. Because in most countries iodine is labeled as total iodine, acceptance of an international standard based on the ICP-MS technique which takes all forms of iodine into account, is recommended. This would help to avoid any potential dispute on the accuracy of labeled iodine concentrations in finished products.

Quadrupole inductively coupled plasma mass spectrometry and sector field ICP-MS: a comparison of analytical methods for the quantification of As, Pb, Cu, Cd, Zn, and U in drinking water

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Héctor Hernández-Mendoza ◽  
Nancy Lara-Almazán ◽  
Abraham Kuri-Cruz ◽  
Elizabeth Teresita Romero-Guzmán ◽  
María Judith Ríos-Lugo
Keyword(s):  
Mass Spectrometry ◽  
Drinking Water ◽  
Inductively Coupled Plasma ◽  
The United States ◽  
Routine Analysis ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Relative Standard ◽  
Plasma Mass Spectrometry ◽  
Precision And Accuracy

Abstract A comparison was carried out between quadrupole inductively coupled plasma mass spectrometry (ICP-QMS) detection and sector field ICP-MS (ICP-SFMS) detection for quantification of elements such as arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), and uranium (U) in drinking water. A drinking water sample obtained from the International Atomic Energy Agency was used for validation measurement methods. ICP-QMS and ICP-SFMS obtained recoveries of 95–107% and 95–105%, respectively. Moreover, the relative standard deviation for ICP-QMS was <5% in comparison with ICP-SFMS, which was <2%. The limits of detection obtained in ICP-MS and ICP-SFMS for each element were under ng L−1, except for Zn. Both methods were applied to evaluate these elements in drinking water for consumption in Mexico. According to Mexican Regulation for Human Drinking Water NOM-201-SSA1-2015 and Environmental Protection Agency (EPA) from the United States, the values are within the allowable limits. In conclusion, ICP-QMS and ICP-SFMS are excellent choices for measurements of these toxic elements in water samples because of high precision and accuracy in routine analysis minutes, while also exhibiting excellent precision and accuracy in routine analysis.

Single Particle Inductively Coupled Plasma Mass Spectrometry: Investigating Nonlinear Response Observed in Pulse Counting Mode and Extending the Linear Dynamic Range by Compensating for Dead Time Related Count Losses on a Microsecond Timescale

2019 ◽  
Author(s):  
Ingo Strenge ◽  
Carsten Engelhard
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Nonlinear Response ◽  
Dynamic Range ◽  
Dead Time ◽  
Inorganic Nanoparticles ◽  
Linear Dynamic Range ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry

<p>The article demonstrates the importance of using a suitable approach to compensate for dead time relate count losses (a certain measurement artefact) whenever short, but potentially strong transient signals are to be analysed using inductively coupled plasma mass spectrometry (ICP-MS). Findings strongly support the theory that inadequate time resolution, and therefore insufficient compensation for these count losses, is one of the main reasons for size underestimation observed when analysing inorganic nanoparticles using ICP-MS, a topic still controversially discussed.</p>

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