Lower Detection Limits Found for Chlorine Dioxide Contaminants

1984 ◽  
Vol 76 (7) ◽  
pp. 98-101 ◽  
Author(s):  
Gilbert Gordon ◽  
Yasuhisa Ikeda
Author(s):  
A. P. Kovarsky ◽  
V. S. Strykanov

GaN epitaxial films were analyzed by Secondary Ion Mass Spectrometry (SIMS). Standard implanted samples were used to determine the appropriate analytical conditions for analysis of impurities. The dose and energy of implantation for selected elements (Mg, Al, Si, Zn, Cd, H, C and O) were chosen so the maximum impurity concentration was not more than 1020 atoms/cm3. The optimum analysis conditions were ascertained from the standards for each element, and the detection limits were deduced from the background levels of the implantation profiles. We demonstate that lower detection limits of 1015 atoms/cm3 with a dynamic range 103 − 105 are possible. Zn and Cd have low ion yields, so the minimum detection level for these elements is the background level of the detector. The detection limits of the other elements are determined by the contamination of an initial GaN matrix.


1980 ◽  
Vol 34 (2) ◽  
pp. 144-146 ◽  
Author(s):  
Jeanne P. Haushalter ◽  
G. Patrick Ritz ◽  
David J. Wallan ◽  
Kathy Dien ◽  
Michael D. Morris

ac-coupled inverse Raman spectroscopy is shown to yield detection limits comparable to those obtained by spontaneous Raman spectroscopy. For an aqueous nitrate ion, inverse Raman limits are about 2.5 times higher than those reported for conventional measurements with similar laser powers and measurement times. Proposed improvements in instrumentation may lower detection limits another 10 times with no change in laser powers or measurement times.


2021 ◽  
pp. 219256822110394
Author(s):  
Jan-Helge Klingler ◽  
Ulrich Hubbe ◽  
Christoph Scholz ◽  
Florian Volz ◽  
Roland Roelz ◽  
...  

Study Design: Prospective cohort study. Objectives: The purpose of this prospective study was to evaluate a protocol for radiation-sparing kyphoplasty by assessing dosemetrically recorded radiation exposures to both patient and surgeon. Methods: This prospective clinical study examines the radiation exposure to patient and surgeon during single-level kyphoplasty in 32 thoracolumbar osteoporotic vertebral body fractures (12 OF 2, 9 OF 3, 11 OF 4 types) using a radiation aware surgical protocol between May 2017 and November 2019. The radiation exposure was measured at different locations using film, eye lens and ring dosemeters. Dose values are reported under consideration of lower detection limits of each dosemeter type. Results: A high proportion of dosemeter readings was below the lower detection limits, especially for the surgeon (>90%). Radiation exposure to the surgeon was highest at the unprotected thyroid gland (0.053 ± 0.047 mSv), however only slightly above the lower detection limit of dosemeters (0.044 mSv). Radiation exposure to the patient was highest at the chest (0.349 ± 0.414 mSv) and the gonad (0.186 ± 0.262 mSv). Fluoroscopy time, dose area product and number of fluoroscopic images were 46.0 ± 17.9 sec, 124 ± 109 cGy×cm2, and 35 ± 13 per kyphoplasty, respectively. Back pain significantly improved from 6.8 ± 1.6 to 2.5 ± 1.7 on the numeric rating scale on the first postoperative day ( P < 0.0001). Conclusions: The implementation of a strict intraoperative radiation protection protocol allows for safely performed kyphoplasty with ultra-low radiation exposure for the patient and surgeon without exceeding the annual occupational dose limits. Trial registration: The study was registered in the German Clinical Trials Register (DRKS00011908, registration date 16/05/2017).


2005 ◽  
Vol 77 (11) ◽  
pp. 3694-3699 ◽  
Author(s):  
Jung-Suk Yoo ◽  
Su-Moon Park

2011 ◽  
Vol 30 (26) ◽  
pp. 3137-3148
Author(s):  
Héla Romdhani ◽  
Lajmi Lakhal-Chaieb

2014 ◽  
Vol 10 (6) ◽  
pp. 2796-2813 ◽  
Author(s):  
Fawzia Ibrahim ◽  
Nahed M El-Enany ◽  
Shereen Shalan

A simple, sensitive and rapid spectrophotometric methods were developed and validated for the determination of two antihypertensive drugs namely, carvedilol and nebivolol hydrochloride in pure form and pharmaceutical formulations. Method (I) is based on the formation of a binary complex between the studied drugs and eosin Y in presence of tween 80 at (pH 3.0).The formed complex exhibited maximum absorption at 545 nm for carvedilol and 543 nm for nebivolol. The concentration plots were rectilinear over concentration range of 0.5-5 and 1-7 µg/mL with lower detection limits of 0.09 and 0.11µg/mL and lower quantitation limits of 0.28 and 0 .34 µg/mL for carvedilol and nebivolol respectively. Method (II) is based on the reaction of studied drugs through their secondary amino groups with 2, 4-dinitrofluorobenzene (DNFB) at pH 8 to form yellow colored reaction products peaking at 383 nm and 390 nm for carvedilol and nebivolol, respectively. The absorbance-concentration plots were rectilinear over the concentration ranges of 5-30 and 4-28 µg/ mLwith the lower detection limits of 0.48 and 0.51 µg/mL and the lower quantitation limits of 1.45 and 1.54 µg/mL for cavredilol and nebivolol respectively. The different experimental parameters affecting the development and stability of the formed complex and reaction products were carefully studied and optimized for both methods. Both methods were successfully applied for determination of the studied drugs in their dosage forms.


2015 ◽  
Vol 7 (11) ◽  
pp. 4552-4559 ◽  
Author(s):  
Mandeep K. Chahal ◽  
Muniappan Sankar

Naphthyridine-based fluorescent chemosensors were prepared. They exhibited a selective dual-channel response to detect F−and Hg2+ions with lower detection limits (0.5–2 ppm range).


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