scholarly journals Experimental and Theoretical Study on the False Positive of Monomethyltin Determination in Toys Based on Gastric Juice Migration

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Lina Huang ◽  
Hanke Li ◽  
Yuhang Li ◽  
Peng Ren ◽  
Lezhou Yi ◽  
...  
Keyword(s):  
Gastric Juice ◽  
False Positive ◽  
Laboratory Testing ◽  
Consumer Products ◽  
Hazardous Substances ◽  
Gas Chromatography Mass Spectrometry ◽  
Tin Compounds ◽  
Real Samples ◽  
False Judgment ◽  
Sodium Tetraethylborate

Background. Organic tin compounds (OTCs), a group of high-risk hazardous substances, are highly concerned in safety regulation of consumer products especially for toys because they can cause serious damage to organs after prolonged or repeated exposure. Gastric juice migration is nowadays widely implemented to assess organic tin intake from toys or food-contact materials; however, the followed up detection method using sodium tetraethylborate [NaB(Et4)] as a derivatization agent may directly lead to false positive of monomethyltins (MMT). Objective. In order to avoid the phenomena of false positive of MMT in the course of laboratory testing of toys, it is necessary and important to perform relative experimental and theoretical studies to reveal the cause of false positive of MMT. Method. With metal tin powder as a representative of inorganic tin which existed in real samples, it was treated with artificial gastric juice (0.07 mol/L·HCl), followed by ethyl derivatization using sodium tetraethylborate [NaB(Et)4] and then analyzed by gas chromatography-mass spectrometry (GC-MS) according to the procedure specified in the standard of EN 71-3:2013+A3:2018 issued by the European Committee for Standardization (CEN). Results. Without any OTCs in the starting materials, MMT false positive can be reproduced by detecting 0.56 mg/L of triethylmethyltin (TEMT) together with approximately 1000 mg/L of tetraethyltin (TeET), which is similar to real samples. Further, it is demonstrated that the detected amount of TEMT is linearly related with the added amount of NaB(Et)4, and that the formation of TEMT (methyl derivative) is easier than TeET (ethyl derivative) even though the ethyl group is present in a larger amount than the methyl group. Conclusions. The phenomena of MMT false positive which occurred in the laboratory testing of toys is mainly because that TEMT is highly likely to be obtained from the reaction of inorganic tin and trace level of methylation agent impurities contained in the derivatization reagent—NaB(Et)4. To avoid MMT false positive, it is concluded that the maximum acceptable mole ratio of methylation agent impurities contained in NaB(Et)4 is approximately 0.028%. This research is helpful to be aware of methylation impurities and is favorable to avoid false judgment caused by MMT false positive in routine analysis of toys.

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

2020 ◽  
Author(s):  
RIn Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
Measurement System ◽  
False Positive ◽  
Laboratory Testing ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

scholarly journals Anthropogenic Occurrence of Phthalate Esters in Beach Seawater in the Southeast Coast Region, South Korea

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 122 ◽  
Author(s):  
Huijin Heo ◽  
Mi-Jin Choi ◽  
Jongkwan Park ◽  
Taewoo Nam ◽  
Jaeweon Cho
Keyword(s):  
South Korea ◽  
Phthalate Esters ◽  
Domestic Sewage ◽  
Consumer Products ◽  
Stir Bar Sorptive Extraction ◽  
Gas Chromatography Mass Spectrometry ◽  
Environmental Matrices ◽  
Sorptive Extraction ◽  
Weather Events ◽  
Butyl Phthalate

In modern times, humans have contributed to the occurrence of phthalate esters (PEs) in various environmental matrices by consuming plastics that generally contain PEs, which are essential synthetic organic chemicals for fabrication of various consumer products. Five beaches in Ulsan and Busan, South Korea, were investigated for the anthropogenic occurrence of four PEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), and bis(2-ethylhexyl) phthalate (DEHP)) in beach seawater. Using stir-bar sorptive extraction-thermal desorption-gas chromatography/mass spectrometry, DnBP and DEHP were determined as generally dominant. At Ilsan Beach, both the northern and southern ends showed higher DnBP and DEHP concentrations than the middle of the beach, while DMP and DEP showed similar concentrations at all points. The differences in the DnBP and DEHP concentrations may be related to the fishery industry and domestic sewage inflow to the beach. In addition, a comparison among Ilsan, Imnang, and Songjeong beaches suggested the effects of neighboring industrial areas on the DnBP and DEHP ratio. This study provides information on the effects of seasons, weather events, the proximity of rivers, industrial behavior, and domestic sewage to PE concentrations in beach seawater.

Kavain Interference with Amphetamine Immunoassay

2020 ◽  
Author(s):  
H Madhavaram ◽  
T Patel ◽  
C Kyle
Keyword(s):  
False Positive ◽  
Cross Reactivity ◽  
Drug Prevention ◽  
Urine Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Piper Methysticum ◽  
Fragmentation Pattern ◽  
Aboriginal Communities ◽  
Australian Aboriginal ◽  
Positive Urine

Abstract We encountered unexpected false-positive urine results in three patients for amphetamine-type substances by immunoassay (IA), measured as part of community drug prevention programs. Kavain was identified in all three urine samples by gas chromatography-mass spectrometry (GC-MS). No other potential cross-reactants were found. Kavain is a kava-lactone present in kava, a ceremonial and recreational drink derived from the roots and stems of the plant Piper methysticum. It is consumed regularly by many indigenous Pacific and Australian Aboriginal communities. Urine IA was performed on a Beckman Coulter AU480 Analyzer using cloned enzyme donor immunoassay (CEDIA) amphetamine-type substance reagent and DRI ethanol reagent. We purchased three different kava powders from local kava clubs and dissolved in ethanol, then evaporated and reconstituted in blank urine and analyzed by IA, GC-MS for amphetamine-type substances. Additionally, authentic kavain standard was also tested for cross-reactivity by IA and analyzed by GC-MS to compare the mass fragmentation pattern and retention time with the kava powder and patient specimens. The patient urine samples tested positive by CEDIA IA for amphetamines. However, when analyzed by GC-MS, they were negative for amphetamine-type but contained kavain. The kava powders and kavain standard all cross-reacted with the amphetamine IA to give falsely detected results. GC-MS did not identify any amphetamine-type compounds in any of the kava powders nor in the kavain standard. To our knowledge, this is the first report of false-positive amphetamine measurements due to kavain, a component of the kava drink, widely consumed in Oceania and Australasia.

scholarly journals The Cannabinoid Content of Legal Cannabis in Washington State Varies Systematically Across Testing Facilities and Popular Consumer Products

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Nick Jikomes ◽  
Michael Zoorob
Keyword(s):  
Relative Stability ◽  
Laboratory Testing ◽  
Consumer Products ◽  
Washington State ◽  
Biochemical Profile ◽  
Pharmacologically Active ◽  
Pharmacologically Active Compounds ◽  
Testing Protocols ◽  
The U.S ◽  
Over Time

Abstract The majority of adults in the U.S. now have state-legal access to medical or recreational cannabis products, despite their federal prohibition. Given the wide array of pharmacologically active compounds in these products, it is essential that their biochemical profile is measured and reported to consumers, which requires accurate laboratory testing. However, no universal standards for laboratory testing protocols currently exist, and there is controversy as to whether all reported results are legitimate. To investigate these concerns, we analyzed a publicly available seed-to-sale traceability dataset from Washington state containing measurements of the cannabinoid content of legal cannabis products from state-certified laboratories. Consistent with previous work, we found that commercial Cannabis strains fall into three broad chemotypes defined by the THC:CBD ratio. Moreover, we documented systematic differences in the cannabinoid content reported by different laboratories, relative stability in cannabinoid levels of commercial flower and concentrates over time, and differences between popular commercial strains. Importantly, interlab differences in cannabinoid reporting persisted even after controlling for plausible confounds. Our results underscore the need for standardized laboratory methodologies in the legal cannabis industry and provide a framework for quantitatively assessing laboratory quality.

From Compliance to Rulemaking: How Global Corporate Norms Emerge from Interplay with States and Stakeholders

2012 ◽  
Vol 13 (5) ◽  
pp. 381-418 ◽  
Author(s):  
Olaf Dilling
Keyword(s):  
International Organizations ◽  
Consumer Products ◽  
Hazardous Substances ◽  
Global Markets ◽  
Society Business ◽  
Regulatory Issues ◽  
Cross Border ◽  
Global Trend ◽  
Global Problems ◽  
Do So

Many industrial practices, such as the organization of working conditions or the use of hazardous substances, are no longer endemic to a specific jurisdiction. Rather, they spread through cross-border production chains or global markets for consumer products. In many cases, such regulatory issues therefore cannot be resolved within a single territory. Instead, they require the involvement of global players, such as civil society, business actors or international organizations, who can often find pragmatic solutions to global problems, even if they lack the formal authority to do so. This seems to conform to a more global trend of national government getting replaced by global governance.

scholarly journals Screening analysis of RoHS directive hazardous substances (phthalate esters and bromodiphenyl ethers) by novel mass spectrometry using soft ionization

2019 ◽  
Vol 6 (2) ◽  
pp. 181469
Author(s):  
Masataka Ohgaki ◽  
Yuko Takeguchi ◽  
Shin Okawa ◽  
Kenji Namiki
Keyword(s):  
Mass Spectrometry ◽  
Phthalate Esters ◽  
Screening Method ◽  
Hazardous Substances ◽  
Gas Chromatography Mass Spectrometry ◽  
The European Union ◽  
Pyrolysis Gas ◽  
Standard Material ◽  
Soft Ionization ◽  
Rohs Directive

In 2013, the European Union expanded the list of hazardous substances contained in the RoHS Directive. In addition, certain phthalate esters, such as dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DIBP), will be categorized as RoHS-prohibited substances starting from July 2019. Although pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS) is a promising analytical method for the screening of phthalate esters, we have developed a novel soft-ionization MS method that is quantitative as well as faster and more convenient for this purpose. The sample was measured three times, after providing the calibration curve using a powdery standard material of SPEX. The data collection time is 5 min, and continuous measurements are completed within 8 min per sample. The mass spectrum was corrected by dividing the intensity by the sample weight. For the coefficient of variation, DBP was 2.9%, BBP was 3.4%, DEHP was 3.6%, and good reproducibility was observed. Precise analyses of phthalate esters using traditional methods can require solvent extraction times of up to 24 h as well as special techniques. Therefore, a screening method that can be easily carried out by anyone within ten minutes is very attractive.

Do all screening immunoassay positive buprenorphine samples need to be confirmed?

2017 ◽  
Vol 54 (6) ◽  
pp. 707-711
Author(s):  
Mohamed Saleem ◽  
Helen Martin ◽  
Anne Tolya ◽  
Penny Coates
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
False Positive ◽  
Clinical Care ◽  
Cross Reactivity ◽  
Gas Chromatography Mass Spectrometry ◽  
Potential Cost Saving ◽  
Potential Cost ◽  
Chromatography Mass Spectrometry ◽  
Mass Spectrometry Assay

Background Interference from opiates in the Microgenics CEDIA® Buprenorphine assay is known to produce false-positive buprenorphine screening immunoassay results necessitating confirmatory buprenorphine testing by chromatography/mass spectrometry methods. Method We reviewed data on falsely positive buprenorphine immunoassay screen (cut-off ≥ 5  µg/L) but negative for buprenorphine by gas chromatography mass spectrometry (cut-off ≥ 5  µg/L) and had a positive opiate immunoassay result (cut-off ≥ 300  µg/L). The results were collected over three months, and the data were evaluated to determine whether there is an opiate immunoassay screen concentration below which a false-positive buprenorphine result will not occur. Results We found that cross-reactivity in the CEDIA® buprenorphine immunoassay by opiates at concentrations <2000  µg/L will not cause a false-positive buprenorphine result. After changing our practice to not proceed with confirmatory buprenorphine gas chromatography mass spectrometry assay when the opiate screening concentration is below an even more conservative cut-off of <1500  µg/L, we estimate a potential cost-saving of AU$ 17,810 per year without compromising clinical care. Conclusion Samples with CEDIA® opiate immunoassay result <2000  µg/L and a positive CEDIA® buprenorphine immunoassay screen do not require confirmatory testing for buprenorphine.

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