Method Detection Limit Determination and Application of a Convenient Headspace Analysis Method for Methyltert-Butyl Ether in Water

2002 ◽  
Vol 74 (22) ◽  
pp. 5907-5911 ◽  
Author(s):  
Dennis T. O'Neill ◽  
Elizabeth A. Rochette ◽  
Philip J. Ramsey
2003 ◽  
Vol 75 (6) ◽  
pp. 1555-1555
Author(s):  
Dennis T. O'Neill ◽  
Elizabeth A. Rochette ◽  
Philip J. Ramsey

2019 ◽  
Vol 70 (2) ◽  
pp. 475-482
Author(s):  
Cristian Catalin Gavat ◽  
Leonard Vasile Vasilescu ◽  
Afrodita Doina Marculescu

The aim of this research was to exactly quantify pure sodium metamizole from tablets , using a spectrophotometric analysis in Visible range. The method applied has been subjected to a validation protocal which consisted in analyzing the following parameters: linearity of the method, detection limit (LD) , quantitation limit (LQ), Sandell�s sensitivity, interference of excipients, stability of prepared solutions, method and system precision, accuracy of the method. Following actual dosing, pure sodium metamizole amount in tablet of pharmaceutical was found to be 477.477 mg assigned to a percentage content of 95.495 %, very close to official declared amount (500 mg), with an maximum average percentage deviation of only 4.505 % from the official declared active substance content. This value was situated below the maximum admissible percentage deviation from stated active substance content (� 5%), established by Romanian Pharmacopoeia, X-th Edition rules.


2016 ◽  
Vol 11 (2) ◽  
pp. 188 ◽  
Author(s):  
Bambang Wispriyono ◽  
Eko Handoyo

<p>Efek negatif dari polusi udara terhadap kesehatan manusia banyak diteliti termasuk polusi akibat sistem transportasi. Emisi kendaraan bermotor menghasilkan Benzena, Toluena dan Xylena (BTX) yang merupakan bahan kimia yang bersifat karsinogenik dan petugas pintu tol merupakan kelompok berisiko terpajan BTX. Penelitian bertujuan mengetahui risiko kesehatan akibat pajanan BTX pada petugas pintu tol. Desain penelitian adalah <em>cross-sectional</em> dengan pendekatan Analisis Risiko Kesehatan Lingkungan (ARKL) dan  faktor-faktor antropometri. Hasil penelitian menunjukkan pada pintu tol rata-rata konsentrasi (mean<span style="text-decoration: underline;">+</span>SD) benzena sebesar 0,00167<span style="text-decoration: underline;">+</span>0,000056 mg/m<sup>3</sup>, toluena sebesar 0,00124<span style="text-decoration: underline;">+</span>0.000049 mg/m<sup>3</sup> dan xylena sebesar 0,00147<span style="text-decoration: underline;">+</span>0,000063 mg/m<sup>3</sup> sedangkan pada kantor administrasi konsentrasi tidak terdeteksi oleh alat (<em>Method Detection Limit</em>). Rata-rata risiko non karsinogenik (RQ) BTX pada petugas pintu tol lebih tinggi secara signifikan dibandingkan dengan rata-rata RQ BTX petugas administrasi. Risiko kesehatan non karsinogenik dan karsinogenik belum menunjukkan adanya risiko kesehatan yang signifikan. Upaya pencegahan berupa pengelolaan manajemen risiko untuk pengendalian risiko bahan berbahaya di lingkungan perlu ditingkatkan.</p><p> </p><p><strong>Kata Kunci:</strong> Pintu Tol, Benzena, Toulena, Xylena</p><p> </p><p>The researches of BTX (Benzene, Toluene and Xylene) related to the health impacts have been done and published in any publications. One of the risk groups is toll gate’s workers who have been exposed every day with BTX. The design of this study is cross-sectional with Environmental Health Risk Analysis to determine the magnitude of health risks of BTX on the toll gate. The results showed at the toll workers’s respondents have  benzene concentration 0.00167+0.000056 mg/m<sup>3</sup>, toluene 0.00124+0.000049 mg/m<sup>3</sup> and xylene 0.00147+0,000063 mg/m<sup>3</sup> respectively, while in the administrative office’s respondents, BTX was undetectable (Minimum Detection Limit). The average RQ of toll gate respondents was significantly higher than administrative office’s respondents. In conclusion, the risk of all workers have the RQ ≤ 1. Non carcinogenic and carcinogenic health risks to all toll gate’s workers recently have not shown any risk yet. Nevertheless, risk management system should be developed and improved.</p><p> </p><p><strong>Keywords</strong>: Toll Gate, Benzene, Toulene, Xylene</p>


1994 ◽  
Vol 77 (5) ◽  
pp. 1288-1292 ◽  
Author(s):  
Nancy J Miller-Ihli

Abstract A method was developed for the determination of lead in sugars and syrups. Samples are wet-ashed with a nitric acid–hydrogen peroxide procedure and analyzed by graphite furnace atomic absorption spectrometry. The method involves the use of magnesium nitrate as a matrix modifier, air ashing, platform atomization, and quantitation by peak area measurements with direct calibration against aqueous standards. The instrumental detection limit (based on 3.29σ) was 10 pg, or 0.5 μg/L for a 20 μL injection, corresponding to a method detection limit of 3.3 ng/g sugar. The characteristic mass was approximately 12 pg. This method was validated by analyzing sucrose and high-fructose corn syrup samples spiked with known quantities of lead. The average recovery was 101 ± 6%.


Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 746
Author(s):  
Kunho An ◽  
Inhwan Kim ◽  
Chan Lee ◽  
Joon-Kwan Moon ◽  
Hee-Jae Suh ◽  
...  

Morpholine salts of fatty acids have been used in wax coatings on the surfaces of fruit and vegetable commodities in China and the United States, etc. However, morpholine usage was prohibited in many other countries because of safety concerns. We optimized analytical methods to determine morpholine in the peel and pulp of fruits and vegetables by gas chromatography-mass spectrometry (GC-MS). This morpholine analysis method was applied to real samples of apples, citrus fruits, and vegetables from Korea, China, and the U.S. The method was validated using apple and citrus fruit peels and pulp. The method detection limit (MDL) was 1.3–3.3 µg/kg. The recovery rates of morpholine were 88.6–107.2% over a fortified level of 10–400 µg/kg. Intra-day and inter-day precisions were 1.4–9.4% and 1.5–2.8%, respectively. The morpholine concentrations were n.d. (not detected)–11.19 and n.d. (not detected)–12.82 µg/kg in apple and citrus peels, respectively. Morpholine was not detected in citrus or apple pulp samples or in vegetable samples.


1992 ◽  
Vol 75 (2) ◽  
pp. 334-340 ◽  
Author(s):  
Denis B Page, ◽  
Henry B.S Conacher, ◽  
Dorcas Weber, ◽  
Gladys Lacroix,

Abstract Recent findings of benzene In several fruit-flavored mineral waters at low μg/kg levels, reportedly arising from added benzoate, have prompted a survey of various fruits, juices, and drinks for traces of benzene. Headspace sampling, capillary gas chromatography, and mass spectrometrlc detection enabled detection with confirmation (full-scan spectrum) of benzene as low as 0.03 μg/kg. With selected Ion monitoring, the method detection limit was 0.02 μg/kg, I.e., 3 times the analytical blank, in total, 97 samples were analyzed. Benzene was found at levels ranging from 0.018 to 3.83 μg/kg. Samples labeled to contain added benzoate or believed to contain natural benzoate, such as cranberries, were found to contain benzene at higher levels (n = 41, av. 0.66 μg/kg) than other samples (n = 32, av. 0.082 μg/kg). Average levels of benzene In fruits (as expressed juice), In juices with and without benzoate, In noncarbonated drinks with and without benzoate, and in soft drinks with and without benzoate were 0.042,0.672,0.056,0.395, 0.116,0.793, and 0.062 μg/kg, respectively


Author(s):  
Amitesh Malhotra ◽  
Banu Örmeci

Abstract Effective monitoring tools and methods are needed for the early detection and management of cyanobacteria in water bodies to minimize their harmful impacts on the environment and public health. This research investigated changing the cuvette pathlength (10-, 50-, and 100-mm) to improve the detection of cyanobacteria using UV-Vis spectrophotometry with subsequent application of derivative spectrophotometry and Savitzky-Golay (S-G) transformation. A non-toxigenic strain of blue-green cyanobacteria, Microcystis aeruginosa (CPCC 632), and a green algae strain for comparison, Chlorella vulgaris (CPCC 90), were studied in a wide range of concentrations (955,000–1,855 cells/mL). In each concentration range, method detection limits were established with absorbance measurements and S-G first derivative of absorbance using 10-, 50-, and 100-mm cuvette pathlengths. Increasing the cuvette pathlength from 10 to 100 mm resulted in a 15-fold improvement in sensitivity with absorbance and a 13-fold improvement with S-G first derivative of absorbance for M. aeruginosa. Overall, adoption of 100 mm pathlength and application of S-G derivative spectra improved the method detection limit for M. aeruginosa from 337,398 cells/mL to 4,916 cells/mL, which is below the WHO guideline for low probability of adverse health effects (&lt;20,000 cells/mL). Similarly, the detection limit for C. vulgaris was improved from 650,414 cells/mL to 11,661 cells/mL. The results also showed that spectrophotometry could differentiate M. aeruginosa from C. vulgaris based on the variations in their pigment absorbance peaks.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Sònia Moret ◽  
Manuela Hidalgo ◽  
Juan M. Sanchez

Two concentration methods for fast and routine determination of caffeine (using HPLC-UV detection) in surface, and wastewater are evaluated. Both methods are based on solid-phase extraction (SPE) concentration with octadecyl silica sorbents. A common “offline” SPE procedure shows that quantitative recovery of caffeine is obtained with 2 mL of an elution mixture solvent methanol-water containing at least 60% methanol. The method detection limit is 0.1 μg L−1 when percolating 1 L samples through the cartridge. The development of an “online” SPE method based on a mini-SPE column, containing 100 mg of the same sorbent, directly connected to the HPLC system allows the method detection limit to be decreased to 10 ng L−1 with a sample volume of 100 mL. The “offline” SPE method is applied to the analysis of caffeine in wastewater samples, whereas the “on-line” method is used for analysis in natural waters from streams receiving significant water intakes from local wastewater treatment plants.


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