Precise determination of aquatic plant wet mass using a salad spinner

2016 ◽  
Vol 73 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Tobias Oliver Bickel ◽  
Christine Perrett
Keyword(s):  
Aquatic Plant ◽  
Plant Biomass ◽  
Dry Mass ◽  
Precise Determination ◽  
Freshwater Ecosystems ◽  
Mass Measurements ◽  
Accuracy And Precision ◽  
Reliable Assessment ◽  
Macrophyte Species

The reliable assessment of macrophyte biomass is fundamental for ecological research and management of freshwater ecosystems. While dry mass is routinely used to determine aquatic plant biomass, wet (fresh) mass can be more practical. We tested the accuracy and precision of wet mass measurements by using a salad spinner to remove surface water from four macrophyte species differing in growth form and architectural complexity. The salad spinner aided in making precise and accurate wet mass with less than 3% error. There was also little difference between operators, with a user bias estimated to be below 5%. To achieve this level of precision, only 10–20 turns of the salad spinner are needed. Therefore, wet mass of a sample can be determined in less than 1 min. We demonstrated that a salad spinner is a rapid and economical technique to enable precise and accurate macrophyte wet mass measurements and is particularly suitable for experimental work. The method will also be useful for fieldwork in situations when sample sizes are not overly large.

scholarly journals Ecotypes of Aquatic Plant Vallisneria americana Tolerate Different Salinity Concentrations

2020 ◽  
Author(s):  
Mohsen Tootoonchi ◽  
Lyn Gettys ◽  
Kyle Thayer ◽  
Ian Markovich ◽  
Joseph Sigmon ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Aquatic Plant ◽  
Plant Biomass ◽  
Visual Quality ◽  
Freshwater Ecosystems ◽  
Control Treatment ◽  
Vallisneria Americana ◽  
Abiotic Conditions ◽  
Saline Solutions ◽  
Normal Salinity

Increased salinity caused by saltwater intrusion or runoff from de-icing salts can severely affect freshwater vegetation and deteriorate aquatic ecosystems. These habitats can be restored with freshwater ecotypes (locally adapted populations) that tolerate above-normal salinity. Vallisneria americana is a prominent species in many freshwater ecosystems that responds differently to abiotic conditions such as substrate composition and fertility, so in this study we evaluated the effects of salt stress on 24 ecotypes of V. americana. Instant Ocean aquarium salt was used to create saline solutions [0.2 to 20.0 parts per thousand (ppt)], then plants were abruptly exposed to these solutions and maintained in these concentrations for 5 weeks before being visually assessed for quality and destructively harvested. Analysis of variance and non-linear regression were used to calculate LC50 values – the lethal concentration of salt that reduced plant biomass and quality by 50% compared to control treatment. Growth rate and visual quality varied significantly among ecotypes, and ecotypes that were most and least sensitive to salt had 50% biomass reductions at 0.47 and 9.10 ppt, respectively. All ecotypes survived 10.0 ppt salinity concentration but none survived at 20.0 ppt, which suggests the maximum salinity concentration tolerated by these ecotypes is between 15.0 and 20.0 ppt.

scholarly journals Ecotypes of Aquatic Plant Vallisneria americana Tolerate Different Salinity Concentrations

Diversity ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 65
Author(s):  
Mohsen Tootoonchi ◽  
Lyn A Gettys ◽  
Kyle L Thayer ◽  
Ian J Markovich ◽  
Joseph W Sigmon ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Aquatic Plant ◽  
Plant Biomass ◽  
Visual Quality ◽  
Freshwater Ecosystems ◽  
Control Treatment ◽  
Vallisneria Americana ◽  
Abiotic Conditions ◽  
Saline Solutions ◽  
Normal Salinity

Increased salinity caused by saltwater intrusion or runoff from de-icing salts can severely affect freshwater vegetation and deteriorate aquatic ecosystems. These habitats can be restored with freshwater ecotypes (locally adapted populations) that tolerate above-normal salinity. Vallisneria americana is a prominent species in many freshwater ecosystems that responds differently to abiotic conditions such as substrate composition and fertility, so, in this study, we evaluated the effects of salt stress on 24 ecotypes of V. americana. Instant Ocean aquarium salt was used to create saline solutions (0.2 to 20.0 parts per thousand (ppt)), then plants were abruptly exposed to these solutions and maintained in these concentrations for five weeks before being visually assessed for quality and destructively harvested. Analysis of variance and nonlinear regression were used to calculate LC50 values—the lethal concentration of salt that reduced plant biomass and quality by 50% compared to control treatment. Growth rate and visual quality varied significantly among ecotypes, and ecotypes that were most and least sensitive to salt had 50% biomass reductions at 0.47 and 9.10 ppt, respectively. All ecotypes survived 10.0 ppt salinity concentration but none survived at 20.0 ppt, which suggests that the maximum salinity concentration tolerated by these ecotypes is between 15.0 and 20.0 ppt.

PRECISE DETERMINATION OF THE IRRATIONAL PRE-FERRED INTERFACE ORIENTATION BY TEM

2010 ◽  
Vol 46 (4) ◽  
pp. 411-417 ◽  
Author(s):  
Yang MENG ◽  
Lin GU ◽  
Wenzheng ZHANG
Keyword(s):  
Precise Determination ◽  
Interface Orientation

Determination of Selected Phthalates in Some Commercial Cosmetic Products by HPLC-UV

2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural
Keyword(s):  
High Performance ◽  
Phthalate Esters ◽  
High Sensitivity ◽  
Hplc Method ◽  
Cosmetic Products ◽  
Limit Of Quantification ◽  
Nail Polish ◽  
Accuracy And Precision ◽  
Butyl Phthalate

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.

Recent Applications of High Performance Thin Layer Chromatography and Derivative Spectrophotometry in Pharmaceutical Analysis

2020 ◽  
Vol 16 (6) ◽  
pp. 671-689
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Katarzyna Mądra-Gackowska ◽  
Piotr Kośliński ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Pharmaceutical Analysis ◽  
High Performance ◽  
Degradation Products ◽  
Derivative Spectrophotometry ◽  
Accuracy And Precision ◽  
Post Marketing ◽  
Layer Chromatography

At present, no one can imagine drug development, marketing and post-marketing without rigorous quality control at each stage. Only modern, selective, accurate and precise analytical methods for determination of active compounds, their degradation products and stability studies are able to assure the appropriate amount and purity of drugs administered every day to millions of patients all over the world. For routine control of drugs simple, economic, rapid and reliable methods are desirable. The major focus of current scrutiny is placed on high-performance thin layer chromatography and derivative spectrophotometry methods, which fulfill routine drug estimation’s expectations [1-4]. The present paper reveals state-of-the-art and possible applications of those methods in pharmaceutical analysis between 2010 and 2018. The review shows advantages of high-performance thin layer chromatography and derivative spectrophotometry, including accuracy and precision comparable to more expensive and time-consuming methods as well as additional fields of possible applications, which contribute to resolving many analytical problems in everyday laboratory practice.

A Green Liquid Chromatographic Method For The Simultaneous Determination of Chlorpheniramine Maleate, Pseudoephedrine Hydrochloride and Propyphenazone

2019 ◽  
Vol 15 (6) ◽  
pp. 635-641
Author(s):  
Nadia M. Mostafa ◽  
Ghada M. Elsayed ◽  
Nagiba Y. Hassan ◽  
Dina A. El Mously
Keyword(s):  
Simultaneous Determination ◽  
Mobile Phase ◽  
Dosage Form ◽  
Chromatographic Method ◽  
Green Analytical Chemistry ◽  
Chlorpheniramine Maleate ◽  
Accuracy And Precision ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Background:The concept of green analytical chemistry prevails due to the growing environmental pollution.Objective:Our attempts are to develop simple and eco-friendly method which is non-harmful to the environment by producing minimal waste. In this context, a green liquid chromatographic method was applied for the simultaneous determination of chlorpheniramine maleate, pseudoephedrine hydrochloride and propyphenazone in their combined dosage form.Methods:Separation was carried out using X select HSS RP C18 analytical column (250 × 4.6 mm, 5μm) using methanol - 0.02 M phosphate buffer pH 3 - triethylamine (60:40: 0.1, by volume) as a mobile phase. The separated peaks were detected at 215 nm at a flow rate 1.0 mL/min.Results:Quantification was done over the concentration ranges of 1-25 µg/mL for chlorpheniramine maleate, 5-35 µg/mL for pseudoephedrine hydrochloride and 10-120 µg/mL for propyphenazone. The suggested method was validated with regard to linearity, accuracy and precision according to the International Conference on Harmonization guidelines with good results.Conclusion:It could be used as a safer alternative for routine analysis of the mentioned drugs in quality control laboratories.

A Rapid Method for Determination of Buprenorphine and Norbuprenorphine in Urine by UPLC-MS/MS

2020 ◽  
Vol 16 ◽  
Author(s):  
Aykut Kul ◽  
Murat Ozdemir ◽  
Selma Ozilhan ◽  
Olcay Sagirli
Keyword(s):  
Forensic Science ◽  
Rapid Method ◽  
Proficiency Testing ◽  
Mass Spectrometer ◽  
Illicit Market ◽  
Analysis Methods ◽  
Accuracy And Precision ◽  
Lower Limits

Background: Buprenorphine is quite common in the illicit market. Buprenorphine-containing drugs abuse is frequently encountered in patients. The analysis methods used to determine the abuse of buprenorphine and norbuprenorphine are important for forensic science. Buprenorphine is metabolized to norbuprenorphine by the liver. Objective: Therefore, the determination of buprenorphine and norbuprenorphine in urine is one of the methods to determine the abuse of buprenorphine. Methods: In this study, we have developed a precise, simple, and rapid ultra-performance liquid chromatographytandem mass spectrometer method for the determination of buprenorphine and norbuprenorphine simultaneously. Results: The developed method was validated in terms of selectivity and linearity, which was in the range of 9–1800 ng/mL for both buprenorphine and norbuprenorphine. The intra-assay and inter-assay accuracy and precision were found within acceptable limits of the EMA guideline. Lower limits of quantitation were 9 ng/mL for both buprenorphine and norbuprenorphine. Conclusion: The developed method was successfully applied for the determination of both analytes in the proficiency testing samples.

Nauwkeurige methode voor de aanwasbepaling van het grondvlak met behulp van de Pressler-boor

1968 ◽  
Vol 12 ◽  
Author(s):  
R. Goossens
Keyword(s):  
Basal Area ◽  
Precise Determination ◽  
Maximum Diameter ◽  
Precise Method ◽  
Maximum Radius ◽  
The Core ◽  
Two Parameters

A precise method for the determination of the increment of the  basal area using the PressIer bore. Refering to  previous research showing that the basal area of the corsica pine could be  characterized by an ellips, we present in this paper a precise method for the  determination of the increment of the basal area. In this method we determine  the direction of the maximum diameter, we measure this diameter and we take a  core in one of the points of tangency of the caliper with the measured tree.  The determination of the diameter perpendicular to the maximum diameter  finishes the work wich is to be done in the forest. From the classical  measurements effectuated on the core and from the measured diameters we can  then determine the form (V) and the excentricity (e). Substituting these two  parameters in the formula 2 or 2', we can also calculate the error of a  radius measured on the core with respect to the representative radius, This  error with them allow us to correct the measured value of the minimum or the  maximum radius and we will be able to do a precise determination of the  increment.

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