How to get rid of carryover on my HPLC autosampler?

I have an Shimadzu SIL-20A which has a very good specification among autosampler in the market. I am analyzing POEA-15 (polyehtoxylated tallow amine) a non-ionic surfactant on a reversed-phase...

10 November 2016 2,846 32 View

Which LC/MS instrument I should purchase to use it Kazakhstan so I can get good performance and especially service/availablity?

If I need to use LC/MS instrument to screen chemicals in food in Kazakhstan's lab, which brand I should choose in term of price, performance, and particularly service, availability, and ease of...

07 August 2016 1,299 8 View

Can anyone help me to extract paraquat/diquat from potato?

I am using the published method to extract paraquat/diquat from potato. I used 10 g sample shake with 1:1 MeOH:0.1 N HCl for 10 min and heat in a water bath at 80 C for 15 min and shake more for...

31 December 2014 9,160 9 View

Do you have any recovery issues with lipophilic pesticides?

With sample:solvent ratio of 1:2 (5 g with 10 mL acetonitrile), you have good overall recovery. I used 0.5 g of oil with 30 mL acetonitrile just to maintain amount of oil at 0.5 g for fear of...

11 December 2014 1,577 9 View

The retention time of glyphosate is less than the void volume retention time. What is your opinion on this?

This publication uses a column 150 x 4.6 mm, the void volume of this column is 1.75 mL. At the flow rate of 1.2 mL/min, the non-retain peak should be out at 1.75/1.2 = 1.45 min. However, the...

08 September 2014 2,555 11 View

How to extract ethylene thiourea (ETU) and propylene thiourea (PTU) from appled?

I have a tough nut to crack. I spiked a mixed standard (Amitrole, ETU, PTU, Cyromazine, Mepiquat, Chlormequat, and Daminozide into 10 g apple and stored them in a freezer over the weekend and...

01 January 1970 3,931 5 View

What for your compound?

01 January 1970 635 1 View

Would you please give any suggest of Thiram extraction in sample?

I try to analyzed Thiram as an intact molecule by LC/MS in the vegetable sample. I can get good peak shape of Thiram standard in acetonitrile using a mixed-mode column. The calibration is good...

01 January 1970 736 10 View

Binary Logistic Generalized Linear Mixed model in SPSS. Is it doable?

I want to analyses the proportion of swimming sperm of three species of fish in two salinities. To analyse the proportion of swimming sperm in a Generalized Linear Model, I would use a Binary...

03 March 2021 2,297 3 View

Good morning research fellows, Has anyone worked with senna alata plant extract on any kind of fish?

Literatures on the piscicidal effect of sennaa alata is scanty. if you have any related litrature either in the bark, leaves or roots used as treatment to any aquatic organism please kindly help...

28 February 2021 9,138 2 View

Experimental Design: How deal with pseudreplicates with immunological and clinical-chemical paramaeters?

Hello everybody, I am investigating the influence of a toxinon various clinical-chemical and haematological parameters in fish. I have three treatments (control, low dose, high dose) in my...

24 February 2021 1,243 1 View

Hi i want to ask that in order to find out LC 50 (96 hours) of particular toxin for fish. Should we keep the animals with food or without food?

if we expose the fish after acclimatization to particular toxin in order to find out LC 50 (96 hours).Should we keep the fish off feed or with feed for that duration. Some literature show that...

24 February 2021 357 2 View

Phenol-pH graphic?

We want to use phenol pH graphic to measure the pH of mediums before and after inhibitor application to cells. We have phenol absorbence values at 460, 560 and 720 nm wavelength. When we measure...

20 February 2021 7,700 3 View

Measuring Total immunoglobulin whole-body of fish larvae?

Hi Dear All, I prepared the extract of fish larvae whole body with PBS. Then protein concentration of the whole-body extraction samples determined by the Folin-Ceiocalteu-Phenol method (Lowry...

17 February 2021 1,971 3 View

What is the identity of additional bands found during fish gut microbiome 16S V4 PCR amplification?

Hi, I am carrying out test PCRs for 16S amplicon sequencing on Illumina MiSeq. I am using standard V4 primers: 515F/806R. The aim is to profile the microbiome of fish guts under different...

16 February 2021 5,668 6 View

Is this the fragment of a sauropod tooth?

Dear colleagues. Fragments of this species are very rare from a terrestrial Lower Cretaceous locality from Germany. Up to now from this locality sauropods could not be proved with certainty. Other...

14 February 2021 2,310 1 View

Problem to dissolve 50%wt Glycerol in 4%wt PVOH 28-99 ??

Hello everyone, I am trying to prepare a solution out of PVA(Polyvinyl alcohol)_Glycerol_Wasser . (4% PVA 28-99 and 50% Glycerin) To prepare this solution I first add PVA to 80degree water and...

06 February 2021 2,300 3 View

What is suitable temperature at reaction mixture of lipase activity assay?

I use para nitrophenyl palmitate substrate with tris buffer ph 8... i read many temperature for Yellow color of para nitro phenol production.. 37 and 50 and 40 at water bath ... I confused as i...

04 February 2021 9,100 5 View