Coupled Plasma Mass Spectrometry Instrument Research Articles

METHOD DEVELOPMENT AND VALIDATION FOR THE DETERMINATION OF ELEMENTAL IMPURITIES IN MEDROXYPROGESTERONE TABLETS 10mg BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

The analytical method development and validation of Medroxyprogesterone tablets 10mg summarizes the outcome of the results for content of Cadmium, Lead, Arsenic, Mercury, and Lithium in by ICP-MS1. The test sample was prepared with microwave assisted acid digestion and introduced into optimized instrumental parameters for use of a quadruple based Agilent 7700 inductively coupled plasma mass spectrometry instrument. This method development and validation by ICP-MS to prove that it is Specific, Precise, Accurate, Linear, Robust, Reproducible and Capable of producing reliable results.

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry Method for Estimation of Elemental Impurities in Calcium Acetate Active Pharmaceutical Ingredient

A sensitive and selective method has been developed and validated for the simultaneous quantitative estimation of aluminum, magnesium, potassium, strontium and sodium in calcium acetate active pharmaceutical ingredient by inductively coupled plasma mass spectrometry. Inductively coupled plasma mass spectrometry is an advanced technique which is capable of analyzing multiple elements simultaneously with high selectivity, sensitivity and much lower detection limit. The test sample was prepared with microwave assisted acid digestion and introduced into optimized instrumental parameters for use of a quadrupole based Agilent 7800 inductively coupled plasma mass spectrometry instrument. Scandium is used as an internal standard in the study. The developed method was validated in terms of specificity, linearity, accuracy, precision, range, limit of detection, limit of quantitation and ruggedness. The results for recoveries of all elements were found between 85.3 to 103.9 %. The relative standard deviation for precision was within 15 %. Calibration plots were linear. The low relative standard deviation values and high recoveries of the method confirm the suitability of the method.

Handling spectral interferences and matrix effects in DRC-ICPMS to assess the elemental profile in human serum samples after dissolution with formic acid

Inductively coupled plasma mass spectrometry instrumentation along with the dynamic reaction cell (DRC) technology has been increasingly used in the last decade for multielemental analysis of biological samples. This work reports the development of a method to assess concentrations of Li, Be, B, Sc, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Cd, Sr, Mo, Pd, Ag, Sb, Te, Cs, Ba, Os, Tl, Pb, and Bi in human serum samples treated with formic acid. This is a single-step procedure that minimizes sample handling and avoids contamination risks and analyte losses. Towards this aim, several experimental conditions such as sample pretreatment with formic acid and instrumental operating parameters were optimized. Interferences due to polyatomic ions were eliminated using DRC with oxygen as reaction gas through the formation of MO+ ions. Our method involved low dilution factors, and appropriate limits of detection in the low μg L−1 range for all elements. The accuracy was evaluated through the analysis of a standard reference material (Inorganic Constituents in Animal Serum, NIST 1598a) and spiked samples, with satisfactory recoveries.

Analysis of Mercury in Wastewater by Microwave Digestion Followed by Inductively Coupled Plasma Mass Spectrometry: Comparison with U.S. Environmental Protection Agency Methods Approved in 40 CFR 136.3

As a cost-saving measure, the use of an existing microwave digestion system and inductively coupled plasma mass spectrometry instrument was investigated for the analysis of mercury in domestic wastewater, industry effluent, stormwater, and other aqueous matrices analyzed under the City of Portland's (Oregon) various National Pollutant Discharge Elimination System (NPDES) permits. A formal alternate test procedure application (ATP) study was undertaken to add total mercury to the analyte list for the CEM microwave digestion method (CEM Corporation, 1992) and for U.S. Environmental Protection Agency (Washington, D.C.) (U.S. EPA) method 200.8, both approved for NPDES work in 40 CFR 136.3 (U.S. EPA, 2001a). The ATP was submitted in March 2005, and final approval was received in November 2006. During the study period and while waiting for approval, all NPDES mercury samples were sent to a contract laboratory for analysis by U.S. EPA method 1631E (U.S. EPA, 2002). Splits were analyzed in-house by the ATP protocol. For treatment plant wastewater and industrial effluents, the 1631E results averaged approximately one-half of those obtained by the ATP method, with a 1% difference slightly above 1000% (order of magnitude) and several in the 200% to 300% range. Preliminary results were confirmed by further studies that compared the ATP method with the room temperature and the heated, closed-vessel digestion option of U.S. EPA methods 245.7 and 1631E (U.S. EPA, 2001b, 2002). This research suggests that the room temperature bromine chloride (BrCl) digestion is ill-suited for the determination of total mercury in wastewater and industrial effluents. Because of the probability of committing type II errors--that is, assuming mercury is present in low concentrations when, in fact, it is not--results for these matrices found using the room temperature BrCl digestion should be interpreted with caution. It is suggested that such results might best be considered "bromine chloride extractable" and, as such, should not be used in studies that require accurate estimates of total mercury.

Elevated Urinary Cr Loss Induces a Reduction in Renal Cr Concentration and the Negative Cr Balance in Streptozotocin-Induced Diabetic Mice

Chromium (Cr) is an essential trace element and is important for normal carbohydrate metabolism, and its deficiency in animals can cause a diabetic-like state. Human and experimental animal studies suggest that urinary Cr excretion is increased in diabetic populations. To investigate whether hyperglycemia-induced elevation of urinary Cr excretion reduces tissue Cr storage conditions, we assessed total Cr balance and Cr distribution in streptozotocin (STZ)-induced diabetic mice. Male C57BL mice were randomly assigned to STZ or control groups and their urine was collected 7, 14, 21 and 28 d after STZ injection. An inductively coupled plasma mass spectrometry instrument equipped with a dynamic reaction cell was used for determination of Cr in urine, plasma and tissues samples. The urinary excretions of Cr were 15.4+/-3.0 and 356+/-62 ng/d, and the renal Cr concentrations were 0.85+/-0.12 and 0.17+/-0.03 ng/mg for the control and diabetes groups, respectively (p<0.01), after 28 d. The Cr balance in STZ-treated mice was distinctly negative due to the increase in urinary Cr loss (p<0.01). These results suggest that in mice, STZ induces a reduction in renal Cr concentration and total negative Cr balance caused by an increase in urinary Cr output.

Enhanced flow injection leaching of rocks by focused microwave heating with in-line monitoring of released elements by inductively coupled plasma mass spectrometry

A focused microwave digestion system was used to heat a mini-column of sample of crushed rock (hematite) during its successive leaching by repeated 250-μL injections of water, HNO 3 1%, 10% and 30% (v/v). The mini-column was connected to the nebulizer of an inductively coupled plasma mass spectrometry instrument, which allowed a continuous monitoring of the progressive release of elements by a given leaching reagent. Quantitation of the accessible fraction of Mg, V, Cr, Mn, Co, Ni, Cu, Zn, Mo, Sb and Pb was done by calibration using 250-μL injections of standard solutions prepared in the leaching reagent matrices. Total digestion of the sample residue was also done to verify mass balance. With the exception of Mg, V and Co, where the same total amount was released with or without microwave heating, an increased release resulted from focused microwave heating, by up to an order of magnitude. Furthermore, mass balance was verified for more elements using microwave heating, presumably because of a lower relative proportion of spectroscopic interference as a result of an increased release of analytes. Using microwave energy in general resulted in the dissolution of additional phases, as evidenced by significantly different 208Pb/ 206Pb ratios as well as the increased release of elements with milder reagents. In fact, in the case of Pb, leaching with 30% HNO 3 was no longer necessary as all the Pb was released in the first three leaching reagents. Microwave heating could therefore be used advantageously in on-line leaching for exploration geochemistry and environmental monitoring.

Validated Measurements of the Uranium Isotopic Signature in Human Urine Samples Using Magnetic Sector-Field Inductively Coupled Plasma Mass Spectrometry

Increased interest in measuring uranium isotope ratios in environmental samples (biological materials, soils, dust particles, water) has come from the necessity to assess the health impact of the use of depleted uranium (DU) based ammunitions during recent military conflicts (e.g., Gulf war, Kosovo) and from the need to identify nondeclared nuclear activities (nuclear safeguards). In this context, very important decisions can arise which have to be based on measurement data of nondisputable uncertainty. The present study describes the certification to 2.5% (k = 2) relative combined uncertainty of n(235U)/n(238U) at ultralow uranium levels (approximately 5-20 pg g(-1)) in human urine samples. After sample decomposition and matrix separation, the isotope ratios were measured by means of a single-detector magnetic sector-field inductively coupled plasma mass spectrometry instrument fitted with an ultrasonic nebulizer. Correction for mass discrimination effects was obtained by means of the certified isotopic reference material IRMM-184. The analytical procedure developed was validated in three complementary ways. First, all major sources of uncertainty were identified and propagated together following the ISO/GUM guidelines. Second, this quality was controlled with a matrix matching NUSIMEP-3 sample (approximately 0.06-0.7% difference from certified). Third, the instrumental part of the procedure was proven to be reproducible from the confirmation of the results obtained for three samples remeasured 7 months later (approximately 1.5% difference). The results obtained for 33 individuals indicated that none seemed to have been exposed to contamination by DU.

Grimm-type Glow Discharge Ion Source for Operation With a High Resolution Inductively Coupled Plasma Mass Spectrometry Instrument

A GD ion source of the Grimm-type design has been developed for operation with a new commercial double focusing ICP-MS instrument capable of higher mass resolution. Instead of introducing only the sample, a complete source arrangement is introduced into the housing of the MS system through a slide valve by a solid insertion probe. Sample changing and source cleaning is fast and the latter reduces the risk of cross contamination to a minimum. The reproducibility of the positioning of the sample and the source is verified by measuring ‘internal’ (reproducibility of the intensity measurements) and ‘external’ (the analysis as a whole when sample changing is included) reproducibilities in analytical determinations. Over the whole mass range, the sensitivity corresponds to that measured with an almost identical GD ion source and a low resolution quadrupole instrument. This demonstrates that element sensitivities are predominantly determined by the processes taking place in and the geometry of the source and not by the ion optics and mass analyser components.

Communication. Oxide and doubly charged ion response of a commercial inductively coupled plasma mass spectrometry instrument

Communication. Oxide and doubly charged ion response of a commercial inductively coupled plasma mass spectrometry instrument

Spectral and physical interferences in a new, flexible inductively coupled plasma mass spectrometry instrument

Different types of interferences in inductively coupled plasma mass spectrometry have been studied on a non-commercial instrument and compared with those reported by other workers. Spectral interferences from plasma and matrix background ions are similar, although relative intensities differ. The extent of formation of oxide and doubly charged ions is quite different from those reported in the literature. Chemical and physical interferences seem not to be present on the new instrument.

System optimisation and the effect on polyatomic, oxide and doubly charged ion response of a commercial inductively coupled plasma mass spectrometry instrument

The practical problems of setting up and operating a commercial inductively coupled plasma mass spectrometry (ICP-MS) instrument for routine analysis are discussed and the effect of choice of operating parameters on performance described. With the instrument used, a VG PlasmaQuad, the major parameter variables, plasma power and gas flows and the aperture-load coil spacing are normally kept constant for routine use. Under these conditions a sufficiently uniform response to a range of elements of different chemistries and atomic mass is obtained for the operator to use the instrument without repeated optimisation throughout the working day even though a variety of different sample types and matrices may be run. At fixed plasma power and spacing the only other critical parameter is the carrier gas flow-rate which is adequately stabilised in the instrument used by a precision mechanical flow regulator. The effect upon performance of variation of this flow-rate is shown for elemental response, doubly charged ion ratio and polyatomic ions and it is demonstrated that setting up for maximum elemental response minimises the effect of these interfering species. In practice carrier gas flow-rate is also normally fixed and setting up the instrument consists only of minor trimming of the ion-lens potentials for optimum response which is usually carried out when starting up for a day's running. Operated in this way the instrument is used for routine analysis by a variety of users on a wide range of matrices. An indication is given of the performance obtained under these conditions.