scholarly journals Development and Validation of an ICP-MS Method for Simultaneous Determination of Selected Metals in Electronic Cigarette Aerosol

Author(s):  
Shintaro Ohashi

SummarySafety and quality standards for electronic cigarettes (e-cigarettes) have been introduced regionally. In 2016, the U.S. Food and Drug Administration (FDA) issued a rule to regulate e-cigarettes, requiring to report harmful and potentially harmful constituents (HPHCs). In the United Kingdom, the British Standards Institution (BSI) specified the metals to be monitored for e-cigarettes. In this study, a method was developed and validated for the simultaneous determination of 13 metals (Be, Al, Cr, Fe, Co, Ni, Cu, As, Se, Ag, Cd, Sn and Pb) in e-cigarette aerosol. Furthermore, matrix effects of major constituents in the aerosol were investigated using glycerol or 1,2-propylene glycol solutions. E-cigarette aerosol was generated by a rotary smoking machine according to CORESTA Recommended Method N° 81 and collected by an electrostatic precipitator coupled to an impinger containing nitric acid. The collected aerosol was dissolved in nitric acid and an aliquot of this solution was analyzed by inductively coupled plasma mass spectrometry (ICP-MS) equipped with a collision/reaction cell.The linearity of the calibration curve was observed in the range of 0.2 to 100 ng/mL for each analyte; the correlation coefficients were 0.998 or larger, the mean recovery of each standard level ranged from 92.6 to 104.5% and the relative standard deviation amounted to max. 9.5%. Accuracy, repeatability and specificity were validated by spiking three different amounts of analytes into e-cigarette aerosol; the mean recovery of each spiking level ranged from 88.7 to 110.3% with a relative standard deviation amounting to max. 9.2% for all analytes. Background contamination from aerosol generation and collection system existed for some analytes, especially for Al, Fe, Cu and Sn. The potential sources of contamination should be identified and controlled to reduce the impact of contamination on quantification. In addition, the actual values for samples should be reported with method blank statistics. Increase of the concentrations of glycerol and 1,2-propylene glycol in the prepared sample led to the overestimation of As and Se. The amount of polyols in the collected aerosol should be monitored and controlled for the accurate quantification of As and Se.

2004 ◽  
Vol 87 (4) ◽  
pp. 847-851 ◽  
Author(s):  
Dorota Kowalczuk ◽  
Hanna Hopkała

Abstract A new second-order-derivative spectrophotometric method using zero-crossing technique measures quinapril (QUI) and hydrochlorothiazide (HYD) in 2-component mixtures. The procedure does not require prior separation of components from the sample. QUI was determined at a wavelength of 211.6 nm (zero-crossing wavelength point of HYD). Similarly, HYD was measured at 270.8 nm (zero-crossing wavelength point of QUI). Calibration graphs were constructed over the concentration range of 4.0 to 24.0 μ/mL for QUI and 2.5 to 15.0 μg/mL for HYD. Detection and quantitation limits were 0.85 and 2.5 μg/mL for QUI and 0.12 and 0.4 μg/mL for HYD, respectively. The accuracy (recovery 100.5–102%), precision (relative standard deviation less than 3.5% for QUI and 1.5% for HYD), selectivity, and sensitivity of the elaborated methods were satisfactory. The proposed method was applied successfully for the determination of both drugs in QUI-HYD tablets.


2008 ◽  
Vol 91 (4) ◽  
pp. 777-785 ◽  
Author(s):  
Pierre Andrieux ◽  
Tamara Kilinc ◽  
Christian Perrin ◽  
Esther Campos-Giménez

Abstract A single-laboratory validation study was conducted for a liquid chromatographic/mass spectrometric (LC/MS) method for the simultaneous determination of the free carnitine and total choline in milk-based infant formula and health-care products. The sample preparation used for both carnitine and choline was adapted from AOAC Official Method 999.14, with an acidic and enzymatic hydrolysis of esterified forms of choline. Carnitine and choline were quantified by ion-pair chromatography with single-quadrupole MS detection, using their respective deuterated internal standards. The repeatability relative standard deviation was 2.5 and 2.1, respectively, for carnitine and choline. The intermediate reproducibility relative standard deviation was <4.7 and 2.4, respectively, for carnitine and choline. The ranges of the average product-specific recoveries were 9298 and 94103, respectively, for carnitine and choline. Choline concentration determined in infant formula reference material SRM 1846 was in agreement with the reference value. The proposed method was compared with the enzymatic methods for a range of products; good correlation (r = 0.99) was obtained, although a significant bias was observed for both analytes. The method, with a short chromatographic run time (7 min), is convenient for routine analysis to enhance analytical throughput and is a good alternative to enzymatic assays.


1982 ◽  
Vol 65 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Patrick J Casey ◽  
Keevin R Speckman ◽  
Frank J Ebert ◽  
William E Hobbs

Abstract A radioisotope dilution (RID) method for the determination of vitamin B12 is presented. The method combines a standard extraction procedure (AOAC 43.108,12th ed.) with a commercially available RID assay kit. The method was evaluated on a wide range of fortified and unfortified food products. Recovery studies on both groups yielded average recoveries of 98.1 and 95.8%, respectively. Reproducibility data generated from replicate analyses on both groups gave a relative standard deviation of 6.9% for the fortified group and 9.2% for the unfortified group. For the samples studied, the mean vitamin B12 content determined by the RID method was 8.01 μg/100 g vs imean of 7.54 μg/100 g by the AOAC microbiological method; the correlation coefficient was r = 0.983.


2005 ◽  
Vol 88 (4) ◽  
pp. 1173-1178 ◽  
Author(s):  
Maria Inés Toral ◽  
Marcelo A Muñoz ◽  
Sandra L Orellana

Abstract A simple method has been developed for the simultaneous determination of N-butylscopolamine bromide and oxazepam in pharmaceutical formulations using first-order digital derivative spectrophotometry. Acetonitrile was selected as the solvent in which both compounds showed well-defined bands. Both analytes showed good stability in this solvent when solutions of the analytes were exposed to light and temperatures between 20° and 80°C. The simultaneous determination of both drugs was performed by the zero-crossing method at 226.0 and 257.0 nm for N-butylscopolamine and oxazepam, respectively. The linear range of determination was found to be 2.5 × 10−7 to 8.0 × 10−5 mol/L for N-butylscopolamine and 7.1 × 10−8 to 8.0 × 10−5 mol/L for oxazepam. A very good level of repeatability (relative standard deviation) of 0.2% was observed for N-butylscopolamine and oxazepam. The ingredients commonly found in pharmaceutical formulations do not interfere. The proposed method was applied to the determination of these drugs in pharmaceutical formulations (capsules).


2016 ◽  
Vol 99 (3) ◽  
pp. 776-785 ◽  
Author(s):  
Louis M Salvati ◽  
Sean C McClure ◽  
Todime M Reddy ◽  
Nicholas A Cellar

Abstract This method provides simultaneous determination of total vitamins B1, B2, B3, and B6 in infant formula and related nutritionals (adult and infant). The method was given First Action for vitamins B1, B2, and B6, but not B3, during the AOAC Annual Meeting in September 2015. The method uses acid phosphatase to dephosphorylate the phosphorylated vitamin forms. It then measures thiamine (vitamin B1); riboflavin (vitamin B2); nicotinamide and nicotinic acid (vitamin B3); and pyridoxine, pyridoxal, and pyridoxamine (vitamin B6) from digested sample extract by liquid chromatography-tandem mass spectrometry. A single-laboratory validation was performed on 14 matrixes provided by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) to demonstrate method effectiveness. The method met requirements of the AOAC SPIFAN Standard Method Performance Requirement for each of the three vitamins, including average over-spike recovery of 99.6 ± 3.5%, average repeatability of 1.5 ± 0.8% relative standard deviation, and average intermediate precision of 3.9 ± 1.3% relative standard deviation.


2001 ◽  
Vol 84 (3) ◽  
pp. 823-846 ◽  
Author(s):  
Philip L Alferness ◽  
Lawrence A Wiebe ◽  
L Anderson ◽  
O Bennett ◽  
M Bosch ◽  
...  

Abstract A collaborative study was conducted to validate a method for the determination of glyphosate and aminomethylphosphonic acid (AMPA) in crops. The analytes are extracted from crops with water, and the crude extracts are then subjected to a cation exchange cleanup. The analytes are derivatized by the direct addition of the aqueous extract into a mixture of heptafluorobutanol and trifluoroacetic anhydride. The derivatized analytes are quantitated by capillary gas chromatography with mass-selective detection (MSD). The collaborative study involved 13 laboratories located in 5 countries 12 laboratories returned valid data sets. The crops tested were field corn grain, soya forage, and walnut nutmeat at concentrations of 0.050, 0.40, and 2.0 mg/kg. The study used a split-level pair replication scheme with blindly coded laboratory samples. Twelve materials were analyzed, including 1 control and 3 split-level pairs for each matrix, 1 pair at each nominal concentration. For glyphosate, the mean recovery was 91%, the average intralaboratory variance, the repeatability relative standard deviation (RSDr), was 11%, and the interlaboratory variance, the reproducibility relative standard deviation (RSDR), was 16%. For AMPA, the mean recovery was 87%, the RSDr was 16%, and the RSDR was 25% at mg/kg levels.


2010 ◽  
Vol 178 ◽  
pp. 361-366
Author(s):  
Yu Shuang Qiao

This paper presents a method for the simultaneous determinat of NP and NPEO1-2 using GC-MS in sludge samples. using ultrasonic extraction, derivatization techniques, the results show that good separation of three substances, a well-shaped peak can be observed on every selected ion chromatogram. the ultrasonic extraction recoveries ranged from 80% to 102% , the instrumental limits of detection for these compounds were 2 ng/g、2 ng/g and 1.5 ng/g and the relative standard deviation(RSD) was below 15%. The establishment of this method provided the method safeguard for the control of NP and NPEO1-2 in sludge samples.


Author(s):  
Vikas Kumar Singh ◽  
Santosh Kumar Verma ◽  
Sudhanshu Ranjan Swain

A highly selective, specific, precise sensitive and reliable ICPMS method has been developed and validated by using ICP-MS for the determination of multielement in Sucroferric oxyhydroxide. The described ICP-MS method provides specific detection and quantification of minor and trace elements from 0.3J(30%) to 2J(200%) of its individual specification of each element i.e Ag, As, Au, Ba, Cd, Co, Cr, Cu, Hg, Ir, Li, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, Tl,  and V.The analytical method found to be Linear for each individual element with working concentration range from 30%, 50%, 100%, 150% and 200% i.e 0.3J, 0.5J, 1J, 1.5J and 2J with correlation coefficient not less than 0.990.The % recoveries of elemental impurities of each individual elements at three different concentrations with spiking in samples were found to be an acceptable range as 70% to 150%.The method was found to be precise and robust and its relative standard deviation was below 20%.The actual observed relative standard deviation in Precision was found to be in an acceptable range. Therefore developed method can be use for routine quantitative analysis of elemental impurities like Ag, As, Au, Ba, Cd, Co, Cr, Cu, Hg, Ir, Li, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru, Sb, Se, Sn, Tl, and V to ensure the quality of drug product.


Author(s):  
P.F. Collins ◽  
W.W. Lawrence ◽  
J.F. Williams

AbstractA procedure for the automated determination of ammonia in tobacco has been developed. Ammonia is extracted from the ground tobacco sample with water and is determined with a Technicon Auto Analyser system which employs separation of the ammonia through volatilization followed by colourimetry using the phenate-hypochlorite reaction. The procedure has been applied to a variety of tobaccos containing from 0.02 to 0.5 % ammonia with an overall relative standard deviation of 2 %. The accuracy of the procedure as judged by recovery tests and by comparison to a manual distillation method is considered adequate


1998 ◽  
Vol 81 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Joanna M Lynch ◽  
David M Barbano ◽  
J Richard Fleming

Abstract The classic method for determination of milk casein is based on precipitation of casein at pH 4.6. Precipitated milk casein is removed by filtration and the nitrogen content of either the precipitate (direct casein method) or filtrate (noncasein nitrogen; NCN) is determined by Kjeldahl analysis. For the indirect casein method, milk total nitrogen (TN; Method 991.20) is also determined and casein is calculated as TN minus NCN. Ten laboratories tested 9 pairs of blind duplicate raw milk materials with a casein range of 2.42- 3.05℅ by both the direct and indirect casein methods. Statistical performance expressed in protein equivalents (nitrogen ⨯ 6.38) with invalid and outlier data removed was as follows: NCN method (wt%), mean = 0.762, sr = 0.010, SR = 0.016, repeatability relative standard deviation (RSDr) = 1.287℅, reproducibility relative standard deviation (RSDR) = 2.146%; indirect casein method (wt℅), mean = 2.585, repeatability = 0.015, reproducibility = 0.022, RSDr = 0.560℅, RSDR = 0.841; direct casein method (wt℅), mean = 2.575, sr = 0.015, sR = 0.025, RSDr = 0.597℅, RSDR = 0.988℅. Method performance was acceptable and comparable to similar Kjeldahl methods for determining nitrogen content of milk (Methods 991.20, 991.21,991.22, 991.23). The direct casein, indirect casein, and noncasein nitrogen methods have been adopted by AOAC INTERNATIONAL.


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