The short version of precision fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-02-24. Anything still debated is marked as such rather than presented as settled.
Routine quality control uses system suitability, blank injections, check standards, and control samples to detect drift or contamination. System suitability criteria may specify minimum resolution, maximum tailing factor, and a permitted range for repeated injections. Blank injections reveal carryover or solvent contamination, while check standards confirm calibration accuracy over a batch. Control samples with known analyte levels can show whether results remain within statistical limits. When a control result falls outside limits, the analyst investigates the cause and may invalidate affected results before repeating the batch.
Documentation and traceability are central to regulated HPLC testing. Records typically include instrument logs, column history, mobile-phase preparation, sample preparation, injection sequences, raw chromatograms, and audit trails. Electronic systems may require user access controls, time-stamped changes, and backup procedures. Training records show that analysts are qualified for assigned methods. Audits and inspections check whether written procedures match actual practice and whether deviations are documented. These controls support reproducibility and allow results to be reconstructed if questions arise later.
Method validation establishes that an HPLC procedure is suitable for its intended purpose. Typical parameters include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, robustness, and solution stability. Accuracy reflects closeness to a reference value, while precision reflects agreement among repeated measurements. Specificity shows whether the method can measure the analyte without interference from matrix components. Validation is documented through protocols and reports, and the required extent depends on the method's use and regulatory context.
Method validation demonstrates that an HPLC procedure is suitable for its intended purpose. Common validation parameters include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantification, and robustness. Accuracy reflects agreement with a reference value, while precision describes repeatability under defined conditions. Specificity shows whether the method can measure the analyte in the presence of impurities or matrix components. Validation documents are reviewed before a method is used for routine testing or regulatory submissions.
System suitability testing is performed before and during analytical runs to confirm that the instrument and method are working as expected. Typical checks include retention time, peak area precision, resolution between critical pairs, tailing factor, and theoretical plate count. Acceptance criteria are set in the method or pharmacopeial monograph. If a suitability check fails, the run may be rejected and the instrument or sample preparation may need investigation. This practice helps prevent release of data from a system that has drifted out of control.
Quality control samples are inserted at intervals to monitor accuracy and precision throughout a batch. Blank samples detect contamination, while spiked samples assess recovery from the sample matrix. Calibration standards establish the relationship between detector response and concentration, and control samples are prepared independently from them whenever possible. Laboratories also participate in proficiency testing and maintain audit trails, instrument logs, and reagent records. Ongoing review of control charts can reveal trends before they cause out-of-specification results.
| Property | Value | Notes |
|---|---|---|
| Accuracy | Recovery near 100% | Depends on acceptance criteria and matrix |
| Precision | Relative standard deviation | Often at or below 2% for replicate injections |
| Limit of detection | Signal-to-noise ratio 3:1 | Approximate and method-specific |
| Limit of quantitation | Signal-to-noise ratio 10:1 | Confirmed by precision and accuracy |
| Resolution | 1.5 or greater | Typical system suitability target |
Validation demonstrates that a method is suitable for its intended use. Typical performance characteristics include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, and robustness. Regulators and standards organizations provide frameworks, but specific requirements depend on the application and jurisdiction. System suitability tests are run before sample analysis to confirm resolution, peak symmetry, retention time repeatability, and sensitivity. A validated method is not permanently fixed; changes may require partial or full revalidation.
Routine HPLC testing depends on controlled reagents, calibrated instruments, and documented procedures. Columns degrade over time, so retention times and peak shapes are monitored for drift. Mobile phases are filtered and degassed to prevent pump damage and detector noise. Reference standards must be traceable and stored under suitable conditions. Data handling systems record injections, calculations, and audit trails. Quality control samples interspersed with unknowns help detect errors during a run.
Developing an HPLC method begins with defining the purpose, such as quantifying a main component, measuring impurities, or confirming identity. Analysts select separation mode, column, mobile phase, detection, and sample preparation based on analyte properties and matrix. Experiments vary solvent strength, pH, buffer type, and temperature to achieve resolution between critical peaks. The goal is a robust method that produces reliable results across instruments and operators. Method development often involves trial runs and statistical optimization.
Data handling and documentation are central to HPLC quality control. Electronic systems should have audit trails that record changes to methods, sequences, and results. Integration parameters, such as peak baseline and threshold, can affect reported areas and must be defined in advance. Out-of-specification results trigger a structured investigation that may include reanalysis, instrument checks, and review of sample preparation. Regulatory inspections often examine raw data, audit trails, and training records to verify that reported results are traceable and reliable.
Method validation establishes that an HPLC procedure is suitable for its intended use. Key parameters include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, and robustness. Accuracy measures agreement with a true or accepted value, while precision describes repeatability and intermediate precision. Specificity confirms that the method measures the analyte without interference from impurities, degradants, or excipients. Validation is documented in a protocol and report, and acceptance criteria are set before experiments begin. Regulatory guidance varies by region, but the general principles are widely harmonized.
System suitability testing is performed before and during analytical runs to confirm that the instrument and method are working as expected. Common checks include retention time, peak area, resolution between critical pairs, tailing factor, and theoretical plate count. Results are compared with predefined limits, and a failed check requires investigation before sample results are reported. Quality control samples at low, middle, and high concentrations are injected at intervals to monitor accuracy and precision. Blank injections detect carryover and contamination, while control charts track performance over time.
Separation modes differ by the chemistry of the stationary phase and the composition of the mobile phase. Reversed-phase testing uses a nonpolar column and polar solvents, making it common for pharmaceutical, environmental, and food analytes. Normal-phase testing uses a polar column and nonpolar solvents for compounds that are poorly retained in reversed-phase systems. Ion-exchange and ion-pair methods separate charged species, while size-exclusion methods sort molecules by hydrodynamic volume. Gradient elution changes solvent strength over time to resolve complex mixtures, and isocratic elution holds solvent composition constant for simpler assays.
Key performance measures include retention time, peak area, peak height, resolution, tailing factor, and plate count. Retention time helps identify a peak under fixed conditions, but confirmation often requires a second method or detector. Peak area and height relate to concentration through calibration curves, which may be linear or nonlinear depending on the detector response. Resolution describes separation between adjacent peaks, while tailing factor and plate count describe peak shape and column efficiency. Performance checks verify these values before and during a run to confirm that the instrument is performing within limits.
=== Strategies === A long-acting insulin is used to approximate the basal secretion of insulin by the pancreas, which varies in the course of the day. NPH/isophane, lente, ultralente, glargine, and detemir may be used for this purpose. The advantage of NPH is its low cost, the fact that you can mix it with short-acting forms of insulin, thereby minimizing the number of injections that must be administered, and that the activity of NPH will peak 4–6 hours after administration, allowing a bedtime dose to balance the tendency of glucose to rise with the dawn, along with a smaller morning dose to balance the lower afternoon basal need and possibly an afternoon dose to cover evening need. A disadvantage of bedtime NPH is that if not taken late enough (near midnight) to place its peak shortly before dawn, it has the potential of causing hypoglycemia. One theoretical advantage of glargine and detemir is that they only need to be administered once a day, although in practice many people find that neither lasts a full 24 hours. They can be administered at any time during the day as well, provided that they are given at the same time every day. Another advantage of long-acting insulins is that the basal component of an insulin regimen (providing a minimum level of insulin throughout the day) can be decoupled from the prandial or bolus component (providing mealtime coverage via ultra-short-acting insulins), while regimens using NPH and regular insulin have the disadvantage that any dose adjustment affects both basal and prandial coverage.
The chemical energy stored in ATP (the bond of its third phosphate group to the rest of the molecule can be broken, allowing more stable products to form, thereby releasing energy for use by the cell) can then be used to drive processes requiring energy, including biosynthesis, locomotion, or transportation of molecules across cell membranes.
Listed below are the athletes who have achieved a 1,000 pounds (453.6 kilograms) or more deadlift, a feat which has been accomplished by only 40 men in history. It includes both strongman and powerlifting deadlifts performed using only the conventional stance. Sanctioned lifts during competitions and exhibitions, as well as unsanctioned lifts during training (with video proof) are included.
Sources: en.wikipedia.org
=== EC 1.14.19 With oxidation of a pair of donors resulting in the reduction of O2 to two molecules of water === EC 1.14.19.1: stearoyl-CoA 9-desaturase EC 1.14.19.2: stearoyl-[acyl-carrier-protein] 9-desaturase EC 1.14.19.3: linoleoyl-CoA desaturase EC 1.14.19.4: acyl-lipid (11-3)-desaturase EC 1.14.19.5: acyl-CoA 11-(Z)-desaturase EC 1.14.19.6: acyl-CoA (9+3)-desaturase EC 1.14.19.7: Now EC 1.11.1.23, (S)-2-hydroxypropylphosphonic acid epoxidase EC 1.14.19.8: pentalenolactone synthase EC 1.14.19.9: tryptophan 7-halogenase EC 1.14.19.10: icosanoyl-CoA 5-desaturase EC 1.14.19.11: acyl-[acyl-carrier-protein] 4-desaturase EC 1.14.19.12: acyl-lipid ω-(9-4) desaturase EC 1.14.19.13: acyl-CoA 15-desaturase EC 1.14.19.14: linoleoyl-lipid Δ9 conjugase EC 1.14.19.15: (11Z)-hexadec-11-enoyl-CoA conjugase EC 1.14.19.16: linoleoyl-lipid Δ12 conjugase (11E,13Z-forming) EC 1.14.19.17: sphingolipid 4-desaturase EC 1.14.19.18: sphingolipid 8-(E)-desaturase EC 1.14.19.19: sphingolipid 10-desaturase EC 1.14.19.20: Δ7-sterol 5(6)-desaturase EC 1.14.19.21: cholesterol 7-desaturase EC 1.14.19.22: acyl-lipid ω-6 desaturase (cytochrome b5) EC 1.14.19.23: acyl-lipid (n+3)-(Z)-desaturase (ferredoxin) EC 1.14.19.24: acyl-CoA 11-(E)-desaturase EC 1.14.19.25: acyl-lipid ω-3 desaturase (cytochrome b5) EC 1.14.19.26: acyl-[acyl-carrier-protein] 6-desaturase EC 1.14.19.27: sn-2 palmitoyl-lipid 9-desaturase EC 1.14.19.28: sn-1 stearoyl-lipid 9-desaturase EC 1.14.19.29: sphingolipid 8-(E/Z)-desaturase EC 1.14.19.30: acyl-lipid (8-3)-desaturase EC 1.14.19.31: acyl-lipid (7-3)-desaturase EC 1.14.19.32: palmitoyl-CoA 14-(E/Z)-desaturase EC 1.14.19.33: Δ12 acyl-lipid conjugase (11E,13E-forming) EC 1.14.19.34: acyl-lipid (9+3)-(E)-desaturase EC 1.14.19.35: sn-2 acyl-lipid ω-3 desaturase (ferredoxin) EC 1.14.19.36: sn-1 acyl-lipid ω-3 desaturase (ferredoxin) EC 1.14.19.37: acyl-CoA 5-desaturase EC 1.14.19.38: acyl-lipid Δ6-acetylenase EC 1.14.19.39: acyl-lipid Δ12-acetylenase EC 1.14.19.40: hex-5-enoyl-[acyl-carrier protein] acetylenase EC 1.14.19.41: sterol 22-desaturase EC 1.14.19.42: palmitoyl-[glycerolipid] 7-desaturase EC 1.14.19.43: palmitoyl-[glycerolipid] 3-(E)-desaturase EC 1.14.19.44: acyl-CoA (8-3)-desaturase EC 1.14.19.45: sn-1 oleoyl-lipid 12-desaturase EC 1.14.19.46: sn-1 linoleoyl-lipid 6-desaturase EC 1.14.19.47: acyl-lipid (9-3)-desaturase EC 1.14.19.48: tert-amyl alcohol desaturase EC 1.14.19.49: tetracycline 7-halogenase EC 1.14.19.50: noroxomaritidine synthase EC 1.14.19.51: (S)-corytuberine synthase EC 1.14.19.52: camalexin synthase EC 1.14.19.53: all-trans-retinol 3,4-desaturase EC 1.14.19.54: 1,2-dehydroreticuline synthase EC 1.14.19.55: 4-hydroxybenzoate brominase (decarboxylating) EC 1.14.19.56: 1H-pyrrole-2-carbonyl-[peptidyl-carrier protein] chlorinase EC 1.14.19.57: 1H-pyrrole-2-carbonyl-[peptidyl-carrier protein] brominase EC 1.14.19.58: tryptophan 5-halogenase EC 1.14.19.59: tryptophan 6-halogenase EC 1.14.19.60: 7-chloro-L-tryptophan 6-halogenase EC 1.14.19.61: dihydrorhizobitoxine desaturase EC 1.14.19.62: secologanin synthase EC 1.14.19.63: pseudobaptigenin synthase EC 1.14.19.64: (S)-stylopine synthase EC 1.14.19.65: (S)-cheilanthifoline synthase EC 1.14.19.66: berbamunine synthase EC 1.14.19.67: salutaridine synthase EC 1.14.19.68: (S)-canadine synthase EC 1.14.19.69: biflaviolin synthase EC 1.14.19.70: mycocyclosin synthase EC 1.14.19.71: fumitremorgin C synthase EC 1.14.19.72: (–)-pluviatolide synthase EC 1.14.19.73: (S)-nandinine synthase EC 1.14.19.74: (+)-piperitol/(+)-sesamin synthase EC 1.14.19.75: very-long-chain acyl-lipid ω-9 desaturase EC 1.14.19.76: flavone synthase II EC 1.14.19.77: plasmanylethanolamine desaturase EC 1.14.19.78: decanoyl-[acyl-carrier protein] acetylenase
Head – face – forehead – jaw – cheek – chin Neck – shoulder Arm – elbow – wrist – hand – finger – thumb Spine – chest Abdomen – groin Hip – buttocks – leg – thigh – knee – calf – ankle – foot – heel – toe Eyes, ears, nose, mouth, teeth, tongue, throat, Adam's apple, breasts, penis, scrotum, vulva, and navel are also superficial structures.
Amino acids are a set of organic compounds that are used by living organisms to synthesise proteins. All amino acids (except glycine) have one or more pairs of stereoisomers, isomers which share the same bond order but are organized differently in 3D space. A given pair of stereoisomers that are optically active and non-superimposable mirror images of each other are called enantiomers; pairs that are not mirror images are diastereomers or epimers. Stereoisomers of the same molecule may undergo reactions (known as racemization or epimerization respective to the type of stereoisomer pair involved) that convert them to other stereoisomers. Biological systems are stereoselective, preferring certain stereoisomers for chemical reactions; living organisms keep all their amino acids in their "left-handed" (L or levo-) forms (a state called homochirality) because they are unable to use the "right-handed" (D or dextro-) forms for protein synthesis. When an organism becomes unable to keep its amino acids in that unbalanced ratio, such as by dying or shedding tissue, the system will proceed towards chemical equilibrium. Measuring the progress of this interconversion reaction allows estimation of an organism's time of death, if environmental variables like moisture and temperature are accounted for.
Elongation factor 4 (EF-4) is an elongation factor that is thought to back-translocate on the ribosome during the translation of RNA to proteins. It is found near-universally in bacteria and in eukaryotic endosymbiotic organelles including the mitochondria and the plastid. Responsible for proofreading during protein synthesis, EF-4 is a recent addition to the nomenclature of bacterial elongation factors. Prior to its recognition as an elongation factor, EF-4 was known as leader peptidase A (LepA), as it is the first cistron on the operon carrying the bacterial leader peptidase. In eukaryotes it is traditionally called GUF1 (GTPase of Unknown Function 1). It has the preliminary EC number 3.6.5.n1.
Sources: en.wikipedia.org
== Influence and reception == Saladino influenced low carb diet entrepreneur Dave Asprey and celebrity Heidi Montag. He has appeared on Joe Rogan's podcast, the first time in 2020, which greatly expanded his audience and profile. Alexei Anisin has written that his medical background and "pseudo-academic" style has allowed Saladino to give a perceived "scientific authority" to his content, while Saladino remains personally accessible to viewers, which in combination with the high production quality of his videos has led his viewers to trust him. Hafiz Rashid of The New Republic has described Saladino as an "infamous pseudoscience health influencer". According to science communicator Joseph A. Schwarcz, "Fearmongering has become an industry, and Saladino is a head honcho in this arena. The usual technique [for Saladino] is to pick a scientific study that finds some risk and then exaggerate it without taking into account type and extent of exposure." Schwarcz says that Saladino "thinks that lamb testicles and raw liver are healthy, and cruciferous vegetables like broccoli, Brussels sprouts, chard and kale are 'bulls–t.' These, Saladino says, should be avoided because 'once chewed they produce sulforaphane, which is toxic to humans.' Actually, sulforaphane has been shown to be an anti-carcinogen".
=== Regulation of the insulin receptor signal === PI3K (phosphoinositide 3-kinase) is one of the important components in the regulation of the insulin signaling pathway. It maintains the insulin sensitivity in the liver. PI-3K is composed of a regulatory subunit (P85) and a catalytic subunit (P110). P85 regulates the activation of PI3K enzyme. In the PI-3K heterodimer (P85-P110), P85 is responsible for the PI3K activity, by binding to the binding site on the insulin receptor substrates (IRS). It was noted that an increase of P85 a (isoform of P85) results in a competition between the later and the P85-P110 complex to the IRS binding site, reducing the PI3K activity and leading to insulin resistance. Insulin resistance refers also to type 2 diabetes. It was also noted that increased serine phosphorylation of IRS is involved in the insulin resistance by reducing their ability to attract PI3K. The serine phosphorylation can also lead to degradation of IRS-1.
== International rules series == Fletcher served as the Australia international rules football team's goalkeeper for five series: the 2005 series, the 2006 series, the 2010 series, the 2014 series, and the 2015 series. Along with Barry Hall, Fletcher was one of Australia's co-captains for the 2006 series. He is regarded as Australia's greatest keeper throughout the series. He retired from top-level football with a final International Rules match, at the 2015 series in Ireland.
== Clinical comparisons of effectiveness == A 2006 review article in the journal "Lasers in Medical Science" compared intense pulsed light (IPL) and both alexandrite and diode lasers. The review found no statistical difference in effectiveness, but a higher incidence of side effects with diode laser-based treatment. Hair reduction after 6 months was reported as 68.75% for alexandrite lasers, 71.71% for diode lasers, and 66.96% for IPL. Side effects were reported as 9.5% for alexandrite lasers, 28.9% for diode lasers, and 15.3% for IPL. All side effects were found to be temporary and even pigmentation changes returned to normal within 6 months. A 2006 meta-analysis of randomized controlled trials found that alexandrite and diode lasers caused 50% hair reduction for up to 6 months, while there was no evidence of hair reduction from intense pulsed light, neodymium-YAG or ruby lasers.
Turkish, an agglutinative language, carries the potential for words of arbitrary length. Muvaffakiyetsizleştiricileştiriveremeyebileceklerimizdenmişsinizcesine, at 70 letters, has been cited as the longest Turkish word. It was used in a contrived story designed to use this word. The word means "As if you would be from those we can not easily/quickly make a maker of unsuccessful ones" and its usage was illustrated as follows:
Sources: en.wikipedia.org
Validation establishes suitability for a new method, while verification confirms that a method works in a specific laboratory. Verification is often used when a validated method is adopted with existing equipment and staff. Both rely on documented acceptance criteria.
Quantification usually compares detector response to a standard curve made from reference standards. The curve may be external, internal, or based on standard addition depending on matrix effects. Results are reported with units and, when required, uncertainty.
Carryover occurs when analyte from a previous injection remains in the system and appears in a later chromatogram. It can come from the injector, column, or tubing. Blank injections and needle washes help detect and reduce it.
Method validation is the documented process of showing that an HPLC procedure produces reliable results for a defined purpose. It examines parameters such as accuracy, precision, specificity, linearity, and robustness. Regulators and quality systems often require validation before routine use.