Indirect information about the geopolymer’s stability can be obtained by measuring both pH and ionic conductivity (IC) over time. To this aim, Milli-Q water (1:10 w:v) was added to the ground and sifted (d < 125 µm) samples. After shaking, waiting for the sedimentation, and filtering (d < 0.45 µm) under vacuum the solutions, the values of pH and ionic conductivity of the eluate were collected after 1 h [3 (link),4 (link)]. IC measurements were performed with a Crison GLP31 (conductivity cell 50 72, made up of glass and platinum, measuring range from 0 to 50,000 µS/cm, temperature range from −35 to 85 °C), whereas pH measurements were performed with a Crison GLP21 (pH measuring range 0–14, reference element of Ag/AgCl with Ag+ ion barrier, operating temperature range −10 to 100 °C). Crison GLP21 and 31 instruments were from Hach Lange Spain, S.L.U, Barcelona, Spain.
Glp 21
Manufactured by Crison
Sourced in Spain
The GLP 21 is a laboratory equipment designed for general laboratory applications. It provides a controlled and stable environment for various experimental procedures. The core function of the GLP 21 is to maintain temperature, humidity, and other environmental parameters within specified ranges to ensure consistent and reproducible results.
Automatically generated - may contain errors
Lab products found in correlation
Glp31, by Crison (3 mentions)
Cm 700 minolta spectrophotocolorimeter, by Konica Minolta (2 mentions)
Labswift aw, by Novasina (1 mentions)
Pr 32, by Atago (1 mentions)
Ltq orbitrap discovery, by Thermo Fisher Scientific (1 mentions)
Kinetex xb c18, by Phenomenex (1 mentions)
Model 7900, by Agilent Technologies (1 mentions)
Ta xtplus texture analyser, by Stable Micro Systems (1 mentions)
Dr 2800 spectrophotometer, by HACH (1 mentions)
Cr 400, by Konica Minolta (1 mentions)
Agilent 7900, by Agilent Technologies (1 mentions)
Cp 3800 gc, by Agilent Technologies (1 mentions)
Multi n c 3100, by Analytik Jena (1 mentions)
0.1 m naoh, by Merck Group (1 mentions)
Ilab 650, by Werfen (1 mentions)
K dlate, by Megazyme (1 mentions)
Zetasizer nano z, by Malvern Panalytical (1 mentions)
Mastersizer 2000, by Malvern Panalytical (1 mentions)
Th 500, by Novasina (1 mentions)
Cary 60, by Agilent Technologies (1 mentions)
42 protocols using glp 21
1
Geopolymer Stability Evaluation via pH and Ionic Conductivity
2
Measuring pH and Water Activity in Salmon Burgers
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The measurement of pH was carried out on 10 g of uncooked samples, homogenized in distilled water (1:10 sample (weight):water (v)) using a pH meter (Crison GLP 21, Crison Instruments S.A., Barcelona, Spain).
The water activity (aw) values were determined in uncooked salmon burgers using a Novasina LabSwift-aw (Lachen, Switzerland).
The water activity (aw) values were determined in uncooked salmon burgers using a Novasina LabSwift-aw (Lachen, Switzerland).
3
Dry Matter and pH Analysis
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The soluble extract was analyzed to determine the dry matter content, and the sample (1 mL) was dried at 105 °C for 48–72 h in an air convective oven (P Theroven, JP Selecta, Barcelona, Spain). The pH value was measured using a pH meter (Crison GLP 21, Crison, Barcelona, Spain), and standard liquids from Crison were used to calibrate the equipment.
4
Fruit Quality Evaluation Protocol
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
For each fruit (4 fruits per genotype, 80 genotypes, 320 fruits in total), firmness, total soluble solids (TSS), and titratable acidity (TA) were determined. Flesh firmness was measured as maximum force, after removing the skin on two opposite sides of each fruit, with a digital penetrometer (Model 53205; TR, Forlí, Italy) equipped with an 8 mm diameter plunger tip. TSS and TA were determined on cortical flesh juice extracted by an automatic juicer (Moulinex, Type BKA1) from one longitudinal half of each fruit. TSS was measured using a portable refractometer (Atago PR-32, Tokyo, Japan), and the results were expressed in °Brix. TA was measured with an automatic titrator Crison GLP 21 (Barcelona, Spain) and determined by titrating 10 mL of flesh juice with 0.1 N NaOH to pH 8.1 endpoint [31 (link)].
5
Monitoring Cheese Ripening Dynamics
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
Samples were weighed to measure losses because of airing during the ripening process, which was calculated as percent by the difference of weight from day 0 to 21. pH was measured using Crison GLP21 equipment (Crison Instruments S.A., Barcelona, Spain). Water activity (aw) was measured during the ripening process using the Lab Partner-aw (Novasina, A.G., Lachen, Switzerland). Analysis of airborne losses, pH, and water activity were carried out at days 0, 7, 14, 21, 35, 50, and 100 from elaboration.
6
Pumpkin pH Evaluation Over Time
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The pH was evaluated on the homogenized pumpkin by a pH meter (Crison GLP 21 Crison Instruments). The pH measurement was carried in triplicate at 0, 4, 7 and 11 days.
7
Potentiometric Iodide Quantification
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
To validate the developed method, a comparison was made between the paper device and the ion-selective electrode method using an iodide combined electrode (Mettler Toledo perfectION combination, DX series half-cells) connected to a potentiometer (Crison GLP 21) for signal measurement.
To perform the potentiometric method, iodide standard solutions in the range of 5 × 10−6 to 5 × 10−3 M were prepared, and the analyte concentrations were calculated by interpolation in the corresponding calibration curve: E = f (log [I−]). For each measurement, 5 mL of standard/sample was mixed with 5 mL of the ionic strength-adjusting solution (0.4 M KNO3).
To perform the potentiometric method, iodide standard solutions in the range of 5 × 10−6 to 5 × 10−3 M were prepared, and the analyte concentrations were calculated by interpolation in the corresponding calibration curve: E = f (log [I−]). For each measurement, 5 mL of standard/sample was mixed with 5 mL of the ionic strength-adjusting solution (0.4 M KNO3).
8
Soil pH and Conductivity Change
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
MilliQ water (1:10 solid-water ratio) was added to the grounded and sifted (d < 125 µm) samples. After shaking the solution, we waited a short time for the solids to sediment prior to our analyses. After waiting for the pH and conductivity stability, the values were collected on samples after 7, 14, 21, and 28 days of curing time, respectively. Ionic conductivity and pH measurements were performed with a Crison GLP31 and Crison GLP21, respectively. All the measurements were made in triplicate to calculate the mean standard deviation.
9
Muscle pH and Colour Analysis
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The raw muscle pH was measured using a digital pH meter. GLP 21 (Crison Instruments, S.A., Barcelona, Spain) Colour measurements the colour values were expressed as L* (lightness), a* (redness/greenness) and b* (yellowness/blueness) according to Hunt (1991) .
10
Electrochemical Monitoring of MBT Transformation
Check if the same lab product or an alternative is used in the 5 most similar protocols
+ Expand
The total organic carbon (TOC) and pH of the medium were measured at the beginning and the end of each batch cycle using a TOC multi N/C 3100 (Analytikjena, Germany) and a pH meter, GLP 21 (Crison Instruments, Spain), respectively. MBT and its transformation products were identified at different times (0, 7.5, 15, 30, and 50 h) during the last batch cycle by HPLC-MS, using a Thermo Scientific LTQ Orbitrap Discovery apparatus equipped with an electrospray interface operating both in positive ion mode (ESI+) and negative ion mode (ESI-). A Phenomenex Kinetex XB-C18 (100 mm × 2.10 mm, 2.6 μm) column was used. Analyses were carried out using full-scan data-dependent MS scanning from m/z 50 to 400. The structures of the transformation products were proposed by interpreting their corresponding MS spectra.
Coulumbic efficiency was calculated according to eq. 1 as:
Where CODin and CODout are the COD concentration of BES influent and effluent, respectively, I is the circulating electrical current (A), M is the weight of 1 mol of COD (32 g•mol -1 ), Q is the influent flow rate (L•d -1 ), e is the number of mol of electrons exchanged per mol of COD equivalent consumed (4 mol•mol -1 ), and F is the Faraday constant (96,485 C•mol -1 ). TOC was converted to COD considering sodium acetate as the sole carbon source.
Coulumbic efficiency was calculated according to eq. 1 as:
Where CODin and CODout are the COD concentration of BES influent and effluent, respectively, I is the circulating electrical current (A), M is the weight of 1 mol of COD (32 g•mol -1 ), Q is the influent flow rate (L•d -1 ), e is the number of mol of electrons exchanged per mol of COD equivalent consumed (4 mol•mol -1 ), and F is the Faraday constant (96,485 C•mol -1 ). TOC was converted to COD considering sodium acetate as the sole carbon source.
About PubCompare
Our mission is to provide scientists with the largest repository of trustworthy protocols and intelligent analytical tools, thereby offering them extensive information to design robust protocols aimed at minimizing the risk of failures.
We believe that the most crucial aspect is to grant scientists access to a wide range of reliable sources and new useful tools that surpass human capabilities.
However, we trust in allowing scientists to determine how to construct their own protocols based on this information, as they are the experts in their field.
Ready to get started?
Sign up for free.
Registration takes 20 seconds.
Available from any computer
No download required
Revolutionizing how scientists
search and build protocols!