The short version of quality control fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-21 and is reviewed periodically as new material appears.
Separation performance depends on particle size, pore size, column length, and the chemistry of the stationary phase. Smaller particles generally improve efficiency but require higher pressure and suitable instrumentation. The mobile phase often contains buffers and organic solvents that influence retention and selectivity. Testing labs select conditions based on the analytes, sample matrix, and required sensitivity. Method development frequently involves screening several columns and solvent mixtures before a final set of conditions is chosen.
High-performance liquid chromatography is an analytical technique that separates components in a liquid sample by passing them through a packed column under pressure. A pump delivers a mobile phase at a controlled flow rate, and an injector introduces the sample into the stream. Differences in how analytes partition between the mobile phase and the stationary phase cause them to exit the column at different times. Detection then records a signal proportional to the amount of each separated substance. The resulting chromatogram provides retention times and peak areas for identification and quantification.
Instrumentation includes a solvent delivery system, an autosampler, a column oven, and one or more detectors. Reversed-phase columns with chemically modified silica are widely used, but normal-phase, ion-exchange, size-exclusion, and affinity modes exist for specific separations. Detectors may rely on ultraviolet absorbance, fluorescence, refractive index, or mass spectrometry. Column temperature, mobile phase composition, and flow rate are adjusted to improve resolution. System pressure is monitored because rising pressure can indicate column blockage or deteriorating packing.
Method validation demonstrates that an analytical procedure is suitable for its intended purpose. Typical validation characteristics include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, and robustness. Regulatory guidance from bodies such as the International Council for Harmonisation and the United States Pharmacopeia outlines expectations, though specific criteria depend on the product and method. System suitability tests are run before sample analysis to confirm resolution, peak symmetry, column efficiency, and injection repeatability. Failure of these checks can invalidate a batch of measurements.
Practical HPLC testing depends on careful sample preparation and instrument maintenance. Samples may require filtration, dilution, pH adjustment, or extraction to avoid column damage and matrix interference. Mobile phases are degassed and filtered, and columns are equilibrated before injection. Common problems include peak tailing, baseline drift, ghost peaks, carryover, and co-elution of analytes. Documentation of instrument logs, calibration records, and electronic audit trails supports data integrity and traceability. Ongoing training and routine maintenance help reduce variability between analysts and laboratories.
| Property | Value | Notes |
|---|---|---|
| Separation principle | Differential partitioning | Analytes distribute between mobile and stationary phases. |
| Mobile phase | Liquid solvent mixture | Composition controls retention and selectivity. |
| Stationary phase | Packed column particles | Often chemically bonded silica. |
| Typical detector | UV-Vis or photodiode array | Mass spectrometry is also common. |
| Common synonym | High-performance liquid chromatography | Abbreviated as HPLC. |
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.
Routine quality control monitors retention time shifts, baseline noise, system pressure, and peak shape. Trends can reveal column aging, mobile phase preparation errors, detector drift, or sample degradation. Corrective actions may include replacing the column, preparing fresh mobile phase, or recalibrating the detector. Stability testing often uses HPLC to measure parent compound loss and degradation product formation. Open questions remain about how accelerated stability results extrapolate to long-term storage under varied conditions.
Quality control for HPLC testing combines scheduled checks, documented procedures, and review of results. Before sample analysis, system suitability testing confirms that the instrument, column, and method meet predefined criteria. Common criteria include resolution between critical peaks, retention time precision, peak tailing, and theoretical plate count. Failure triggers investigation before results are reported. Records link raw data, calculations, instrument logs, and analyst identity to each batch, supporting audits and repeat analysis.
Pheomelanins (US English) or phaeomelanins (UK English) (from Greek φαιός phaios 'grey') impart a range of yellowish to reddish colors. Pheomelanins are particularly concentrated in the lips, nipples, glans of the penis, and vagina. When a small amount of eumelanin in hair (which would otherwise cause blond hair) is mixed with pheomelanin, the result is orange hair, which is typically called "red" or "ginger" hair. Pheomelanin is also present in the skin, and redheads consequently often have a more pinkish hue to their skin as well. Exposure of the skin to ultraviolet light increases pheomelanin content, as it does for eumelanin; but rather than absorbing light, pheomelanin within the hair and skin reflect yellow to red light, which may increase damage from UV radiation exposure. Pheomelanin production is highly dependent on cysteine availability, which is transported into the melanosome, reacting with dopaquinone to form cys-dopa. Cys-dopa then undergoes several transformations before forming pheomelanin. In chemical terms, pheomelanins differ from eumelanins in that the oligomer structure incorporates benzothiazine and benzothiazole units that are produced, instead of DHI and DHICA, when the amino acid L-cysteine is present. Pheomelanins, unlike eumelanins, are rare in lower organisms with claims they are an "evolutionary innovation in the tetrapod lineage" but recent research finds them also in some fish.
Degarelix, sold under the brand name Firmagon among others, is a hormonal therapy used in the treatment of prostate cancer. Testosterone is a male hormone that promotes growth of many prostate tumours and therefore reducing circulating testosterone to very low (castration) levels is often the treatment goal in the management of advanced prostate cancer. Degarelix has an immediate onset of action, binding to gonadotropin-releasing hormone (GnRH) receptors in the pituitary gland and blocking their interaction with GnRH. This induces a fast and profound reduction in luteinizing hormone (LH), follicle-stimulating hormone (FSH) and in turn, testosterone suppression.
=== Glandular tissue === Glandular tissue is the type of epithelium that forms the glands from the infolding of epithelium and subsequent growth in the underlying connective tissue. They may be specialized columnar or cuboidal tissues consisting of goblet cells, which secrete mucus. Several glands contain myoepithelial cells that help in the contraction needed for secretion. There are two major classifications of glands: endocrine glands and exocrine glands:
Some 238U atoms, however, could absorb two additional neutrons (for a total of 17), resulting in 255Es, as well as in the 255Fm isotope of another new element, fermium. The discovery of the new elements and the associated new data on multiple neutron capture were initially kept secret on the orders of the U.S. military until 1955 due to Cold War tensions and competition with Soviet Union in nuclear technologies. However, the rapid capture of so many neutrons would provide needed direct experimental confirmation of the r-process multi-neutron absorption needed to explain the cosmic nucleosynthesis (production) of certain heavy elements (heavier than nickel) in supernovas, before beta decay. Such a process is needed to explain the existence of many stable elements in the universe. Meanwhile, isotopes of element 99 (as well as of new element 100, fermium) were produced in the Berkeley and Argonne laboratories, in a nuclear reaction between nitrogen-14 and uranium-238, and later by intense neutron irradiation of plutonium or californium:
Sources: en.wikipedia.org
==== Malaria ==== The President's Malaria Initiative, started with help from George W. Bush, has contributed to a more than 60% reduction in malaria deaths, saved 7.6 million lives, and prevented 1.5 billion malaria cases globally between 2000 and 2019. PMI has supported malaria prevention and control for over 500 million at-risk people in Africa. However, the USAID funding of PMI has been cut an estimated 47% as of June 2025. In countries such as the Democratic Republic of the Congo (DRC), these funds had supported the supply of antimalarial drugs to numerous health zones, including preventive treatments for pregnant women. Health officials in the DRC reported that the effects of these cuts were already being felt, with increased risk of severe illness and death from malaria among vulnerable populations. Former aid workers and experts also expressed concern that reduced funding undermined disease surveillance systems that help detect malaria and other outbreaks early. Such surveillance not only protects affected countries but also contributes to U.S. health security by limiting the global spread of disease. Aid organizations also highlighted how these cuts create a "vicious cycle," with malnutrition and malaria reinforcing one another. Reductions in U.S. support for nutrition programs increase children's vulnerability to malaria and other diseases, while higher malaria infections can worsen malnutrition.
Most aptamers are based on a specific oligomer sequence of 20-100 bases and 3-20 kDa. Some have chemical modifications for functional enhancements or compatibility with larger engineered molecular systems. DNA, RNA, XNA, and peptide aptamer chemistries can each offer distinct profiles in terms of shelf stability, durability in serum or in vivo, specificity and sensitivity, cost, ease of generation, amplification, and characterization, and familiarity to users. Typically, DNA- and RNA-based aptamers exhibit low immunogenicity, are amplifiable via Polymerase Chain Reaction (PCR), and have complex secondary structure and tertiary structure. DNA- and XNA-based aptamers exhibit superior shelf stability. XNA-based aptamers can introduce additional chemical diversity to increase binding affinity or greater durability in serum or in vivo. As 22 genetically encoded and over 500 naturally occurring amino acids exist, peptide aptamers, as well as antibodies, have much greater potential combinatorial diversity per unit length relative to the 4 nucleic acids in DNA or RNA. Chemical modifications of nucleic acid bases or backbones increase the chemical diversity of standard nucleic acid bases. Split aptamers are composed of two or more DNA strands that are pieces of a larger parent aptamer that has been broken in two by a molecular nick. The ability of each component strand to bind targets will depend on the location of the nick, as well as the secondary structures of the daughter strands. The presence of a target molecule supports the joining of DNA fragments.
== Industrial process design == In a typical scenario, an industrial process will use an extraction step in which solutes are transferred from the aqueous phase to the organic phase; this is often followed by a scrubbing stage in which unwanted solutes are removed from the organic phase, then a stripping stage in which the wanted solutes are removed from the organic phase. The organic phase may then be treated to make it ready for use again. After use, the organic phase may be subjected to a cleaning step to remove any degradation products; for instance, in PUREX plants, the used organic phase is washed with sodium carbonate solution to remove any dibutyl hydrogen phosphate or butyl dihydrogen phosphate that might be present.
=== 1988 === 11 February Running to Time, about the new InterCity 225; the National Express Coaches Rapide service; the project team of the Intercity 225, with project director Mike Rollin, and Mike Newman of GEC; the 225 train had to be delivered on 14 February 1988, with an operational life of thirty years; the InterCity 125 was not intended to have been primarily developed - in a board meeting, the commercial directors were not technologically knowledgeable of trains, and asked about alternatives, to be told by an engineering director that a 125 mph diesel train could be developed in two years, so the HST began at that meeting; the British Rail APT-E prototype, powered by the Leyland 2S/350 gas turbine; in 1974 BR commissioned the APT-P, which had ten years of development, due to the active tilting suspension; the 225 train was possibly to enter service on the UK's only large electrified line, the West Coast Main Line, but the much-straighter and faster East Coast Main Line was being electrified, so BR decided to implement the 225 train on the ECML instead; Crewe railway station, which opened in 1837, and where trains were first built nearby in 1843; Steve Corfield, of Crewe Works; the unsprung mass of a train, and Cardan shafts; Roger Ford of Modern Railways; John Prideaux, director of InterCity; David Carter of DCA in Warwick, who designed the livery; the Modernisation Plan was published in December 1954, which had advocated the electrification of the ECML, and the phasing-out of steam travel; the late-1980s ECML electrification had cost BR £350m - it was not government-funded, with 2,800 miles of copper wire, and 33,000 support masts, overseen by Don Heath; all of the improvements in the UK were on old lines of track, but France and Germany had built entire new electrified lines - the TGV was planned from the mid-1960s; G. Freeman Allen of Jane's World Railways; the 225 train underframe being built at Crewe Works; GEC Traction at Preston, Lancashire, Al Reed, the separately excited (Armature Controlled DC Motor) brushed DC electric motor, and Gerald West; the right-angle gearboxes were built by David Brown Ltd and Voith of Heidenheim an der Brenz in southern Germany; Eric Black of Metro-Cammell in Washwood Heath; the ST41 bogies were made by SIG Combibloc Group of Neuhausen am Rheinfall in Switzerland. Narrated by Robin Ellis, produced by Patrick Uden, directed by Paul Fabricius, made by Uden Associates. 12 February Playing with Fire 17 July The Air Fix!, about aviation safety; a television adaptation of a black comedy theatre production by 35-year-old James Castle, dressed as an airline pilot, largely featuring Turkish Airlines Flight 981, the Ermenonville air disaster, in France on 3 March 1974, to this day the worst airliner crash, without any survivors, with 177 British people killed, when a cargo door ruptured, and the subsequent enquiry led to a cover up by the airline and aviation authority; the DC10 had known design failings in its fuselage, and its cargo door design was known to be faulty by the aircraft manufacturer; the American Airlines Flight 96 crash had happened on 12 June 1972, involving a design failure of the cargo door, but the FAA nonetheless gave the DC-10 a certificate of airworthiness; the DC10 had been rushed into service; James Castle accused the aircraft industry of callous negligence; James Castle had been a British Airways aircraft maintenance technician from 1969 to 1977 at Heathrow Airport; he listed the numbers of children that lost one or both parents in the crash, and the numbers of women who were widowed; the theatre production had been going since December 1986, directed by Caroline Noh Narrated by James Castle, produced by Ben Gooder, made by Uden Associates 24 July Nic's Boat, about Nic Bailey, a 37-year-old architect with Foster and Partners; he designed a 40-ft trimaran, called MTC, for the Carlsberg Single-Handed Trans-Atlantic Race on 5 June 1988; he had helped to design the 1978 Sainsbury Centre for Visual Arts in Norwich and the Renault Centre in Swindon; boat builder Spud Rowsell in Exmouth, with Phil Morrison; the hull cost £46,000, and the rigging cost £46,000; the mast and rigging were fitted at Topsham, Devon; Robin Knox-Johnston; French yacht designer Bruno Fehrenbach; he sailed the Atlantic between the Rhumb Line Route and the Great Circle Route; some yachts made the journey to Newport, Rhode Island in ten days; the yacht mast was constructed by Proctor South West. Produced by Michael Wills, directed by Bob Bee, made by Juniper Productions 31 July The Living Dead 7 August Zen and the Art of TV Manufacture, a Panasonic TV factory in South Wales; in 1933 the company founder Kōnosuke Matsushita established seven guiding commercial principles; the Fidelity TV factory in west London was given one year - 1988 - to turn its fortunes around or be closed; the factory's closure was announced to the workforce on 25 January 1988, with the site closing at the end of July 1988; Amstrad bought the Fidelity name in May 1988. Narrated by Alan Howard, directed by Patrick Uden, produced by Michael Proudfoot, made by Uden Associates 14 August How Good Is Soviet Science?, about the political inhibition of Soviet technology in the 1980s; in many ways the Soviet Union in 1987 was a backward and underdeveloped nation, with food queues; the Soviet system didn't respond to changes in demand - everything was planned years in advance; physicist Alexander Prokhorov, who won the Nobel Prize for Physics in 1964; Russians were proud of mathematicians Pafnuty Chebyshev and Nikolai Lobachevsky; large government centrally planned projects were compatible with the communist system, notably its space programme; by the 1970s, the Russians realised that they were some distance behind other countries, such as in disciplines of computing and genetics; science teaching was emphasised at Soviet schools, and English was well taught as well; after secondary schools, half went into science; theoretical science was where Soviet teaching excelled, such as at the Steklov Institute of Mathematics; Yuri Ovchinnikov wanted to improve Soviet science; in the early 1950s, the Soviet Union tried to ignore the findings of genetics, through the work of Trofim Lysenko, who claimed that genetics was anti-communist, known as Lysenkoism leading to many scientists being imprisoned and executed; in the 1960s, a set of large biological research centres were built at Pushchino; one of the most well-built research institutes was the Shemyakin Institute of Bioorganic Chemistry, for biotechnology; Stalin did not like computer science, and it was largely banned until 1958; the Soviets were always years behind in computer science; the first recognisable transistor Soviet computer was the BESM-6 in the 1960s; later computers were the ES EVM series, copied from the IBM System/360; the Akademgorodok (Academic City) in Novosibirsk; the Institute of Automation and Electrometry researched optical memory on holographic slides to and much work on lasers; collaboration between Soviet research and Soviet industry was long-winded, maybe almost impossible - the centrally planned Soviet industry could not sufficiently adapt for short-term changes, as it had to be monotonously planned years in advance, for mass production; Soviet government research was perhaps excellent nonetheless; not many Soviet scientists could travel to international conferences; dissemination of current worldwide science was limited throughout the Soviet Union, due to widespread government restrictions; Suite No. 2 in B minor, BWV 1067. Narrated by US technology historian Loren Graham, produced by Chris Durlacher, directed by Martin Smith, made by Uden Associates, NDR and WGBH. Shown on Nova on 17 November 1987 and 22 March 1988 21 August Toys for the Boys, about the Williams racing team; Graham Hill and Jim Clark in 1967; Tomorrow's World in 1967, narrated by Derek Cooper; journalist Peter Windsor of Williams; aerodynamicist Frank Dernie, head of research at Williams; Keith Botsford, motor racing editor of the Sunday Times; the German racing manager Alfred Neubauer, in the late 1930s; there were 18 F1 teams, with 7 being British; Mobil Oil paid Williams £2.5m for advertising on the cars of Nigel Mansell and Riccardo Patrese; the Williams FW11; racing driver Howden Ganley; part of a BBC Horizon documentary broadcast on 9 March 1981, featuring the Williams FW07, and likewise narrated by Martin Jarvis and produced by Patrick Uden; engineering director Sir Patrick Head; Bach Mass in B minor; Mike Hawthorn, was killed on a public road, the A3 Guildford bypass, in his Jaguar Mark 1 on 22 January 1959; Canadian Gilles Villeneuve was thrown from his Ferrari, when qualifying for the 1982 Belgian Grand Prix; Swedish Ronnie Peterson, died after an accident on the start line at the 1978 Italian Grand Prix; Italian Elio de Angelis was killed in May 1986 at the Circuit Paul Ricard in south-east France; British Piers Courage burned to death at the 1970 Dutch Grand Prix; Jim Clark hit a tree on 7 April 1968 at the 1968 Deutschland Trophäe in the north-west of Baden-Württemberg; German Jochen Rindt was killed at the 1970 Italian Grand Prix after winning the championship in the same year, which was awarded posthumously; Bach Mass in B minor; Frank Williams had a crash on 8 March 1986 in the south of France, with Peter Windsor, in a Ford Sierra, making him quadraplegic; the Williams wind tunnel; Alan Jones waving the British flag at the 1980 Grand Prix; the 1988 season Williams car had a Judd V8 engine; the closing fanfare of Les préludes by Liszt; the documentary ends with German military march Prussia's Glory. Narrated by Martin Jarvis, produced by Patrick Uden, made by Uden Associates 28 August Cold Spring, Morning Sun, about atomic physicist Joan Hinton and her husband Erwin Engst. Joan's mother was teacher Carmelita Hinton. Joan worked on the top secret Manhattan Project at Los Alamos in 1944 which produced the atomic bombs that were dropped on Hiroshima and Hagasaki in the summer of 1945. After the war, Joan, her brother Bill, and her husband Erwin (Sid) Engst travelled to China to join Mao Ze Dong and the cultural revolution. Over the next five decades, Joan and Sid became pioneers in Chinese agricultural science and technology. Narrated by Liza Goddard, written, produced and directed by Chris Haws, Made by InCA. 18 September Taking the Tunnel, who would be travelling through the Channel Tunnel; the tunnel would open in May 1993; Colin Kirkland, technical director of Eurotunnel; Roger Vickerman of the University of Kent; historian Corelli Barnett, and how France and Germany spent money after the war improving rail infrastructure; journalist Kathy Watson; a working model was built of the two Channel rail terminals; 90% of the tunnel went through chalk; the French end was built much more water-tight than the English end, due to the worse geology; the tunnel was around one mile long at the English end, to meet the French side in 1990; the Single Market would stop duty free sales on the Channel ferries; the former Night Ferry across the Channel, which operated until 30 October 1980; TGV Est would connect Bordeaux, and TGV Nord would connect to Germany, the Netherlands, with a spur to the new tunnel; Richard D. North; tolls on the autoroutes discouraged local traffic, which slowed down British motorways; Daniel Ghouzi of Transmanche; Martin Simmons of Kent County Council; A292 junction of M20; Corelli Barnett believed that the British civil service was best at fudging, whereas the French civil service had been trained differently at the French grandes ecoles; a VTG ship from Dover to Dieppe carried trains; freight journeys over 250 miles were most cost effective by rail, but did lack logistical flexibility at either end; Michael Barclay of Tiphook Rail; a distribution centre in Paddock Wood in Kent, built by the Spanish Transfesa; UIC gauge was the main European gauge for freight; Artura Boix of Transfesa; Richard Hope of Railway Gazette; British trains had a 25 tonne axle weight, more than the European 22 tonnes; early plans for the new Eurostar trains, which would be dual voltage for travelling in England and France; rail writer Geoffrey Freeman Allen; the French trains would leave from the Gard du Nord; customs checks would be at the British end in London, but not in France; British Rail planned a high speed line across Kent to open in 1998 from King's Cross, but it would not open until September 2003, and to London in November 2007; Roger Ford of Modern Railways. Narrated by Geoffrey Palmer, produced by Patrick Uden, directed by Paul Fabricius, made by Uden Associates 25 September Road Test about road transport in the UK; there were two million vehicles in the UK in 1930; a test drive would be conducted from The Point, Milton Keynes at 8.30am to Maidstone, by different routes - Mike McDonald of the University of Southampton and Margaret Bell of the University of Nottingham in a Volvo 850 would go across London, and Peter Bonsall and Howard Kirby of the University of Leeds in a Volkswagen Passat B3, would follow the M25 to the north of London, George Hazel of Napier College and John Wootten in a Ford Granada would follow the M25 south of London, and Martin J. H. Mogridge would take the train on the new Thameslink from Bedford railway station via Blackfriars Railway Bridge; the test would be directed from the Road Traffic Research Centre at Middlesex Polytechnic, with Chris Wright, Peter Hills from Newcastle University, and psychologist Ivan Brown from the Applied Psychology Unit (MRC Cognition and Brain Sciences Unit) in Cambridge; variable-message signs (VMS) on the M6; before joining the M25, the vehicles had an average speed of 50 mph; the early plans in the 1940s for the M25, which the M25 to the south and west of London, now largely follows; when the M25 needed to be built, in the 1960s, many environmental objections had arisen for it to be built; Russ Kane in Capital Radio's Flying Eye; David Marsh at the AA Roadwatch studio in north London; the ramp meter, installed on the M6 by John Wootten; all of London's traffic lights were controlled from a computer centre in Westminster, with software (Split Cycle Offset Optimisation Technique) developed by Dennis Robertson; the Volvo 850 enters London along the Edgware Road and Park Lane to Hyde Park Corner; the prototype Autoguide system invented by Ian Catling; automatic vehicle identification (AVI) and piezoelectric strips developed at the University of Nottingham Department of Civil Engineering, and tested by Peter Davies on the Nottingham ring road, next to the QMC; the Volkswagen Passat arrives first at the Great Danes Hotel, making the 107 miles in two hours seventeen minutes, an average speed of 47 mph; the route south of London - 119 miles, also has a 47 mph average speed; the 96-mile rail journey had an average speed of 35 mph; the programme content would be copied by Top Gear fifteen years later. Narrated by Martin Jarvis, produced by David Sharp, directed by Mike Tomlinson, made by Orlando Productions 9 October Look, No Hands! about technology outpacing human knowledge; Hubert Dreyfus of University of California, Berkeley; Martin Corbett, industrial psychologist at the University of Warwick; work by Mike Cooley, and systems design; mechanical engineer Frederick Winslow Taylor and his meticulous improvements to industrial methods, in his book The Principles of Scientific Management; John Harris, manager of the Rolls-Royce helicopter engine plant at Leavesden, Hertfordshire; perhaps automation in engineering manufacturing processes could perhaps add or enhance, rather than totally replace, which required and produced less directly competent workers. Produced by Debra Hauer, directed by Christopher Rawlence, made by Hauer Rawlence Productions 16 October Spytech, John Pike of the Federation of American Scientists and how the Space Shuttle was built mostly for low Earth orbit reconnaissance satellites; but the Titan 34D was also available for many spy satellite launches; Christopher Andrew of the University of Cambridge; Harry Rositzke of the CIA, and the disastrous Operation Red Sox, from 1949 to 1953; William Colby, Director from 1973 to 1976 of the CIA, and how spying methods that worked in Germany during World War II were simply hopeless in a possibly more bizarre culture of communist eastern Europe in the early 1950s, so Ferret missions by B-29 aircraft over the border were attempted instead, but many were shot down; the Americans decided to go for high-altitude reconnaissance; on 1 May 1960, an aircraft photographing a missile construction factory, pilot was sentenced to 10 years, but released after two years in exchange for Rudolf Abel; H. Keith Melton and notorious improvised technology of the KGB; the Russian defector Stanislav Levchenko; the burst transmission method; camera lenses for spy satellites made by Itek; the Space Shuttle was built to maintain and repair the Key Hole set of spy satellites, such as KH-11 KENNEN, launched by the National Reconnaissance Office (NRO) in 1976, and introduced digital photography, and EOSAT and its Landsat program; Jeffrey T. Richelson, a writer on national security; Major-General George Keegan of the Twenty-Fifth Air Force described how the Soviet Union got to know when spy satellites would be overhead, and would hide anything sensitive; listening satellites sent their data to the NSA at Fort Meade in Maryland, such as data from Magnum, launched by the secret STS-51-C mission in January 1985; Paul Bracken and all-source intelligence fusion; Soviet intelligence in the US was quite widespread, with up to 800 spies operating out of Soviet trade missions, and operated much more widespread than the US had attempted; the new KH-12 satellite, that launched in November 1992, could see through clouds. Narrated by Mike Short, produced by Claudia Milne, made by Twenty Twenty 23 October Bamboo, the importance of bamboo to the Chinese economy; Prof Hsiung Wenyue of the Bamboo Research Centre of Nanjing Forestry University; bamboo structures do not collapse in high winds; over a thousand species of bamboo; bamboo dies out for ten years, then grows again; only 15% of China can be cultivated; bamboo can grow four feet in 24 hours, it is the fastest growing plant; bamboo has a tensile strength twice as much as timber; hospitals in China worked with herbal remedies; bamboo traders had quotas set by the Chinese government; bamboo shoots were mostly exported to Japan; growing bamboo helped soil structure; the Chinese government encouraged the growing of bamboo, as an alternative to timber. Narrated by Jenny Agutter, produced by Michael Blakstad, directed by Patrick Fleming, made by Workhouse Productions, made in cooperation with China Central Television 30 October Heavy Metal, chemist Neil Ward of the University of Surrey, who found abnormal pregnancies; medical doctor Robin Russell-Jones of the Campaign for Lead Free Air; environmental chemist Brian Davies of the University of Bradford; footage from the 1971 BBC A Public Poison, with chemist Derek Bryce-Smith, and Patrick Lawther of St Bartholomew's Hospital; Gloria all'Egitto from Aida by Giuseppe Verdi, with the assembly line of the Rover 800; Robin Brundle; Eric Fountain of Vauxhall Motors; Ojos Criollos by Louis Moreau Gottschalk. Narrated by Catherine Robins, produced by Michael Blakstad, made by Workhouse Productions 13 November Free Flight, about gliding, with Derek Piggott in a Rolladen-Schneider LS4 at Booker Gliding Centre in Buckinghamshire; in the UK there were about 350,000 flights and 2 deaths each year; a Schleicher ASW 24 in a wind tunnel with Loek Boermans at TU Delft Faculty of Aerospace Engineering in the Netherlands; the Schleicher ASH 25 with glider pilot John Jeffries at London Gliding Club west of Dunstable; at Wasserkuppe, a 3,000 ft mountain in the east of Hesse in the centre of Germany is where gliding mostly developed in the 1920s by the Deutsche Forschungsanstalt für Segelflug, due to German powered-aircraft manufacturing being legally restricted; nearby at Poppenhausen, Hesse is Alexander Schleicher GmbH & Co, with designer Gerhard Waibel, where gliders had wings made from carbon fibre, and covered in kevlar for torsional stiffness; the first glider of a contemporary design was the Akaflieg Stuttgart fs24 in 1951. Narrated by Robert Gary 20 November Chaos, Tim Palmer of the ECMWF; mathematician Robert L. Devaney; German mathematician Heinz-Otto Peitgen and fractal geometry; strange attractors in dynamical systems, such as weather systems; David Rand of the University of Warwick, and period-doubling bifurcation, discovered in 1975 by mathematician Mitchell Feigenbaum discovered; fractal landscapes; British mathematician Michael Barnsley, and affine transformations, which are applied to digital image processing; the chaos game; Soviet physicist Lev Landau; physicist Harry Swinney of the University of Texas; economist James B. Ramsey; Ian Stewart of the University of Warwick, and the unpredictable rotation of Hyperion. Written, produced and directed by Chris Haws, the programme was made by Independent Communications Associates (InCA). In 1989, it won the SciTech Award for best scientific documentary. 27 November The Art of Deception, about camouflage, deception, decoys and stealth. The Northrop Grumman B-2 Spirit was first displayed on Tuesday 22 November 1988, just five days before the programme was aired. Featured interviewees include: Richard P. Hallion of Wright-Patterson Air Force Base; Peter Varnish of the Admiralty Research Establishment at Funtington in West Sussex; defence writer Antony Preston; Roy Behrens of the Art Academy of Cincinnati; Lt Col Chris Nash of Surveillance, Target Acquisition, Night Observation and Counter-surveillance (STANOC); Major William Marshak of the AAMRL - now the 711th Human Performance Wing; Captain Brian Perowne, commanding officer of HMS Brazen (F91); aviation writer Bill Sweetman, and Commander Patrick Walker, commanding officer of HMS Trafalgar (S107) a Royal Navy hunter-killer submarine; John Hall of the Admiralty Research Establishment (former Admiralty Experiment Works) at Haslar. Narrated by Nick Chilvers, Written, produced and directed by Chris Haws, made by InCA and WGBH Boston
Epitalon is a synthetic peptide, telomerase activator, and putative anti-aging compound, which was identified as the putative active component of a bovine pineal gland extract known as epithalamin. Most studies on epitalon and epithalamin have been conducted by the St. Petersburg Institute of Bioregulation and Gerontology, primarily overseen by Vladimir Khavinson, in Russia, though in recent years research using epitalon has started to be conducted elsewhere, focusing mainly on its ability to extend telomere length.
Sources: en.wikipedia.org
HPLC separates and detects individual compounds in a liquid sample, producing peaks at characteristic retention times. Peak area or height can be used to estimate concentration when calibrated with known standards. It does not identify unknown compounds with certainty unless additional detectors or reference materials are used.
Pressure drives the liquid mobile phase through a column packed with small particles. Without pressure, flow would be very slow or stop because the packed bed resists liquid movement. Modern pumps maintain a steady flow despite the resistance.
A chromatogram is a plot of detector signal against time after sample injection. Each peak represents a compound or group of compounds eluting from the column. Retention time and peak area are the main measurements read from the plot.
Method validation is the documented process of confirming that an HPLC procedure is suitable for its intended use. It evaluates accuracy, precision, specificity, linearity, range, detection limits, and robustness. Validation criteria depend on the regulatory context and the sample type.